Hey,
just to be sure: What was the exact path used to access the self service? To clarify: The Self Service was integrated into the Portal quite some time ago, with that a dedicated portal called selfservice was provided, meaning that the self service can be reached via https://example.com/univention/selfservice/#/ - On UCS 4.4 there was https://example.com/univention/self-service/ (difference is selfservice instead of self-service), which was technically an UMC module and not a dedicated portal.
That should explain what you are seeing: The first one are left-overs from the old self service module, the latter is the portal of the new one.
Could you try to open the self service as written above without a hyphen? It should look like this:
Regards
Jan-Luca