I did set the smb debug level to 4 now and get the following in log.smbd
[2020/08/11 23:40:37.833893, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.833998, 4, pid=404] ../../source3/smbd/vfs.c:805(vfs_ChDir)
vfs_ChDir to /home/andreasseiler
[2020/08/11 23:40:37.834052, 4, pid=404] ../../source3/smbd/vfs.c:859(vfs_ChDir)
vfs_ChDir got /home/andreasseiler
[2020/08/11 23:40:37.834196, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.834236, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.834260, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.834309, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.834341, 4, pid=404] ../../source3/smbd/open.c:3308(open_file_ntcreate)
calling open_file with flags=0x0 flags2=0x800 mode=0600, access_mask = 0x100080, open_access_mask = 0x100080
[2020/08/11 23:40:37.834374, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.834403, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.834427, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.834471, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.834619, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.834680, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.834778, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.834826, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.835128, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.835173, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.835199, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.835231, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.835379, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.835415, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.835448, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.835496, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.835576, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.835611, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.835633, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.835668, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.864387, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.864435, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.864459, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.864508, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.918442, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.918488, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.918511, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.918558, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.918585, 4, pid=404] ../../source3/smbd/open.c:3308(open_file_ntcreate)
calling open_file with flags=0x0 flags2=0x800 mode=0600, access_mask = 0x100081, open_access_mask = 0x100081
[2020/08/11 23:40:37.918610, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.918650, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.918673, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.918715, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.918807, 3, pid=404] ../../source3/smbd/smb2_server.c:3194(smbd_smb2_request_error_ex)
smbd_smb2_request_error_ex: smbd_smb2_request_error_ex: idx[1] status[NT_STATUS_ACCESS_DENIED] || at ../../source3/smbd/smb2_create.c:296
[2020/08/11 23:40:37.922106, 3, pid=404] ../../source3/smbd/filename.c:1445(get_real_filename_full_scan)
scan dir didn't open dir [.]
[2020/08/11 23:40:37.922149, 3, pid=404] ../../source3/smbd/smb2_server.c:3194(smbd_smb2_request_error_ex)
smbd_smb2_request_error_ex: smbd_smb2_request_error_ex: idx[1] status[NT_STATUS_ACCESS_DENIED] || at ../../source3/smbd/smb2_create.c:296
[2020/08/11 23:40:37.946227, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.946271, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.946293, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.946341, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.946370, 4, pid=404] ../../source3/smbd/open.c:3308(open_file_ntcreate)
calling open_file with flags=0x0 flags2=0x800 mode=0600, access_mask = 0x100081, open_access_mask = 0x100081
[2020/08/11 23:40:37.946415, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.946444, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.946467, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.946510, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.946555, 3, pid=404] ../../source3/smbd/smb2_server.c:3194(smbd_smb2_request_error_ex)
smbd_smb2_request_error_ex: smbd_smb2_request_error_ex: idx[1] status[NT_STATUS_ACCESS_DENIED] || at ../../source3/smbd/smb2_create.c:296
[2020/08/11 23:40:37.948215, 3, pid=404] ../../source3/smbd/filename.c:1445(get_real_filename_full_scan)
scan dir didn't open dir [.]
[2020/08/11 23:40:37.948257, 3, pid=404] ../../source3/smbd/smb2_server.c:3194(smbd_smb2_request_error_ex)
smbd_smb2_request_error_ex: smbd_smb2_request_error_ex: idx[1] status[NT_STATUS_ACCESS_DENIED] || at ../../source3/smbd/smb2_create.c:296
[2020/08/11 23:40:37.973563, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.973610, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.973634, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.973683, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.973712, 4, pid=404] ../../source3/smbd/open.c:3308(open_file_ntcreate)
calling open_file with flags=0x0 flags2=0x800 mode=0600, access_mask = 0x100081, open_access_mask = 0x100081
[2020/08/11 23:40:37.973741, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.973767, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:37.973790, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:37.973833, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:37.973918, 3, pid=404] ../../source3/smbd/smb2_server.c:3194(smbd_smb2_request_error_ex)
smbd_smb2_request_error_ex: smbd_smb2_request_error_ex: idx[1] status[NT_STATUS_ACCESS_DENIED] || at ../../source3/smbd/smb2_create.c:296
[2020/08/11 23:40:38.001325, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:38.001368, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:38.001391, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:38.001440, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:38.001469, 4, pid=404] ../../source3/smbd/open.c:3308(open_file_ntcreate)
calling open_file with flags=0x0 flags2=0x800 mode=0600, access_mask = 0x100081, open_access_mask = 0x100081
[2020/08/11 23:40:38.001497, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:38.001523, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:38.001546, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:38.001615, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:38.001708, 3, pid=404] ../../source3/smbd/smb2_server.c:3194(smbd_smb2_request_error_ex)
smbd_smb2_request_error_ex: smbd_smb2_request_error_ex: idx[1] status[NT_STATUS_ACCESS_DENIED] || at ../../source3/smbd/smb2_create.c:296
[2020/08/11 23:40:38.030653, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:38.030701, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:38.030726, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:38.030775, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:38.030804, 4, pid=404] ../../source3/smbd/open.c:3308(open_file_ntcreate)
calling open_file with flags=0x0 flags2=0x800 mode=0600, access_mask = 0x100081, open_access_mask = 0x100081
[2020/08/11 23:40:38.030830, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:38.030857, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:38.030905, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:38.030958, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:38.031052, 3, pid=404] ../../source3/smbd/smb2_server.c:3194(smbd_smb2_request_error_ex)
smbd_smb2_request_error_ex: smbd_smb2_request_error_ex: idx[1] status[NT_STATUS_ACCESS_DENIED] || at ../../source3/smbd/smb2_create.c:296
[2020/08/11 23:40:39.873469, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:39.873538, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:39.873562, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:39.873626, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:39.873655, 4, pid=404] ../../source3/smbd/open.c:3308(open_file_ntcreate)
calling open_file with flags=0x0 flags2=0x800 mode=0600, access_mask = 0x100081, open_access_mask = 0x100081
[2020/08/11 23:40:39.873687, 4, pid=404] ../../source3/smbd/sec_ctx.c:216(push_sec_ctx)
push_sec_ctx(3000024, 5001) : sec_ctx_stack_ndx = 1
[2020/08/11 23:40:39.873713, 4, pid=404] ../../source3/smbd/uid.c:576(push_conn_ctx)
push_conn_ctx(2067482063) : conn_ctx_stack_ndx = 0
[2020/08/11 23:40:39.873736, 4, pid=404] ../../source3/smbd/sec_ctx.c:320(set_sec_ctx_internal)
setting sec ctx (0, 0) - sec_ctx_stack_ndx = 1
[2020/08/11 23:40:39.873778, 4, pid=404] ../../source3/smbd/sec_ctx.c:438(pop_sec_ctx)
pop_sec_ctx (3000024, 5001) - sec_ctx_stack_ndx = 0
[2020/08/11 23:40:39.873900, 3, pid=404] ../../source3/smbd/smb2_server.c:3194(smbd_smb2_request_error_ex)
smbd_smb2_request_error_ex: smbd_smb2_request_error_ex: idx[1] status[NT_STATUS_ACCESS_DENIED] || at ../../source3/smbd/smb2_create.c:296