Same problem here. Unfortunately I can’t even login as a normal user to sogo. In the sogo logs I find the following:
mailcow-sogo-mailcow-1 | Sep 7 15:21:54 bbcd099f5b07 sogod [81]: SOGoRootPage successful login from '77.23.xxx.xxx' for user 'my@email.de' - expire = -1 grace = -1
mailcow-sogo-mailcow-1 | Sep 7 15:21:54 bbcd099f5b07 sogod [81]: 77.23.117.22 "POST /SOGo/connect HTTP/1.0" 200 55/89 0.023 - - 0 - 13