Samba sync stopped

I’m running an UCS primary (jupiter.domain.com) and backup (saturn.domain.com), both with Samba installed. Some days ago it stopped synchronizing ldap to samba what results in

UCS rejected

    1:   UCS DN: uid=portainer,cn=users,dc=domain,dc=com
          S4 DN: cn=portainer,cn=users,DC=domain,DC=com
         Filename: /var/lib/univention-connector/s4/1663069324.489936

    2:   UCS DN: uid=testuser,cn=users,dc=domain,dc=com
          S4 DN: <not found>
         Filename: /var/lib/univention-connector/s4/1663069658.550255

    3:   UCS DN: cn=Jamf User,cn=groups,dc=domain,dc=com
          S4 DN: <not found>
         Filename: /var/lib/univention-connector/s4/1663069661.691615

    4:   UCS DN: uid=testuser,cn=users,dc=domain,dc=com
          S4 DN: <not found>
         Filename: /var/lib/univention-connector/s4/1663069664.046123


S4 rejected


	last synced USN: 14842

I think, I tried everything what mentioned here without any success. What can I do for synching again?

This helped
https://help.univention.com/t/samba-4-rid-pool-renewal/6431