UCS 4.4.x bind9.service not starting (cannot open /etc/bind/named.conf.samba4)

After an unclean system powerdown and fsck the bind9 serive is not starting anymore:
loading configuration from ‘/etc/bind/named.conf.samba4’
13-Jan-2022 21:38:15.205 open: /etc/bind/named.conf.samba4: permission denied
strace: (named -g -c /etc/bind/named.conf.samba4 -d 9)
open("/etc/bind/named.conf.samba4", O_RDONLY) = -1 EACCES (Permission denied)

when named ist started as user bind (named -g -u bind-c /etc/bind/named.conf.samba4 -d 9) the conf files are working (open("/etc/bind/named.conf.samba4", O_RDONLY) = 8) but the zone files cannot be read (thats ok)

file permissions are 644

please help!