Initial sync join to a windows AD domain cannot work reliably without throwing errors

I’m still trying to get a decent trial of the core edition 4.4 working before looking at committing to UCS

due to USC continaully corrupting the actual aD servers in production when doing a “bi-directional sync”, i have moved it to a virtual model of our the network.

the UCS comes up fine with zero errors, but random users & groups throw errors, some items are fine others will not sync.

I have looked at these users and can find no difference with other users that sync.

29.07.2020 16:08:41.375 LDAP        (PROCESS): sync to ucs:   [         group] [    modify] cn=domain guests,cn=groups,dc=backup-ab01,dc=org,dc=disny,dc=com
29.07.2020 16:08:41.647 LDAP        (PROCESS): sync to ucs:   [            ou] [       add] OU=GP1 Office,dc=backup-ab01,dc=org,dc=disny,dc=com
29.07.2020 16:08:42.298 LDAP        (PROCESS): sync to ucs:   [          user] [       add] uid=shawn.zheng,ou=leave user,dc=backup-ab01,dc=org,dc=disny,dc=com
29.07.2020 16:08:43.632 LDAP        (ERROR  ): Unknown Exception during sync_to_ucs
29.07.2020 16:08:43.632 LDAP        (ERROR  ): Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/univention/connector/__init__.py", line 1326, in sync_to_ucs
    result = self.add_in_ucs(property_type, object, module, position)
  File "/usr/lib/python2.7/dist-packages/univention/connector/__init__.py", line 1146, in add_in_ucs
    return bool(ucs_object.create())
  File "/usr/lib/python2.7/dist-packages/univention/admin/handlers/__init__.py", line 557, in create
    dn = self._create(response=response, serverctrls=serverctrls)
  File "/usr/lib/python2.7/dist-packages/univention/admin/handlers/__init__.py", line 1298, in _create
    six.reraise(exc[0], exc[1], exc[2])
  File "/usr/lib/python2.7/dist-packages/univention/admin/handlers/__init__.py", line 1282, in _create
    self.lo.add(self.dn, al, serverctrls=serverctrls, response=response)
  File "/usr/lib/python2.7/dist-packages/univention/admin/uldap.py", line 865, in add
    raise univention.admin.uexceptions.ldapError(_err2str(msg), original_exception=msg)
ldapError: No such object

29.07.2020 16:08:43.632 LDAP        (WARNING): sync to ucs was not successfull, save rejected
29.07.2020 16:08:43.632 LDAP        (WARNING): object was: CN=shawn.zheng,OU=Leave user,DC=gp01,DC=org,DC=disny,DC=com
29.07.2020 16:08:43.772 LDAP        (PROCESS): sync to ucs:   [            ou] [       add] OU=Leave user,dc=backup-ab01,dc=org,dc=disny,dc=com
29.07.2020 16:08:44.714 LDAP        (PROCESS): sync to ucs:   [          user] [       add] uid=binsheng.zeng,ou=sample room,ou=gpc office,dc=backup-ab01,dc=org,dc=disny,dc=com
29.07.2020 16:08:44.720 LDAP        (ERROR  ): Unknown Exception during sync_to_ucs
29.07.2020 16:08:44.720 LDAP        (ERROR  ): Traceback (most recent call last):
  File "/usr/lib/python2.7/dist-packages/univention/connector/__init__.py", line 1326, in sync_to_ucs
    result = self.add_in_ucs(property_type, object, module, position)
  File "/usr/lib/python2.7/dist-packages/univention/connector/__init__.py", line 1146, in add_in_ucs
    return bool(ucs_object.create())
  File "/usr/lib/python2.7/dist-packages/univention/admin/handlers/__init__.py", line 554, in create
    self._ldap_pre_ready()
  File "/usr/lib/python2.7/dist-packages/univention/admin/handlers/users/user.py", line 1634, in _ldap_pre_ready
    raise univention.admin.uexceptions.primaryGroupWithoutSamba(self['primaryGroup'])
primaryGroupWithoutSamba: cn=GP01 USER,ou=gp1 office,dc=backup-ab01,dc=org,dc=disny,dc=com

29.07.2020 16:08:44.720 LDAP        (WARNING): sync to ucs was not successfull, save rejected
29.07.2020 16:08:44.721 LDAP        (WARNING): object was: CN=binsheng.zeng,OU=Sample Room,OU=GPC Office,DC=gp01,DC=org,DC=disny,DC=com