Invalid credentials for Administrator


since 4 weeks, I notice a very strange behaviour on one UCS:
Every monday morning, the administrator isn’t allowed to login into the UMC anymore.

The logs show this message, despite there hasn’t be a password change and if I check the last password change in the LDAP, it’s timestamp is correct from my last manual change.

14.09.20 09:41:08.923  MAIN        ( PROCESS ) : LDAP bind for user 'uid=Administrator,cn=users,dc=dmz,dc=germany-live,dc=de'.
14.09.20 09:41:08.924  MAIN        ( ERROR   ) : LDAP authentication for 'uid=Administrator,cn=users,dc=dmz,dc=germany-live,dc=de' failed: {'desc': 'Invalid credentials'}

I have to set the password with
udm users/user modify --dn uid=Administrator,cn=users,$(/usr/sbin/ucr get ldap/base) --set password=[password] --set overridePWHistory=1 --set overridePWLength=1
to reenable UMC logins again.

I’m short of writing a small cron job to do this every monday at night, but this can’t be a real solution and I have no idea, where this issue comes from.

Any help to debug and fix this issue is appreciated.

Thank and wbrgds,