Comment 2 for bug 1807246

Hi the only thing that comes to my mind would be the default values of the enumeration cache timeouts. those are in the 2-5 minute range.

Check [1] for enum_cache_timeout and related entries.
Maybe create a script that does "while true; sleep 10s; date; check UID; done"
Then you can check how long it takes to forget in your case.
Bump all kind of these timeouts and repeat.
If it helps take them back one by one until you have found which timeout it is in your case.
Then we would at least already know which sub-cache it is that forgets your user.

You could also play with the "enumerate" option in general.
What have you set atm, how does it behave when you switch it to the other value .
Something like [3] could be related to that.

Also could you check your logs if it could be anything like [2] as it reads very similar.

I also asked a friend actually knowing sssd better than I do, maybe he has some hints later on.

[1]: http://manpages.ubuntu.com/manpages/bionic/man5/sssd.conf.5.html
[2]: https://www.linuxquestions.org/questions/linux-server-73/sssd-forgets-group-name-4175577727/
[3]: https://bugzilla.redhat.com/show_bug.cgi?id=1359208