pam and SSH don't cooperate atm in gnomeos
I setup a laptop with gnomeos to have a machine to test the new releases on etc. I enabled sshd and tweaked /etc/sshd_config but it would still reject authentication attempts.
What fixed it was copying /etc/pam.d/sshd to /etc/pam.d/ssh which was missing.
There was a related MR on fd.o that has been backported to 20.08 already that's relevant. https://gitlab.com/freedesktop-sdk/freedesktop-sdk/-/merge_requests/2762
This needs further investigation, mostly an issue so we don't forget.