I think I have the same problem as 2dadsgn. Also running a clean virtualized docker install (esx hypervisor).
I believe this is the forum post that lead to the PR you’ve seen:
https://forum.chirpstack.io/t/login-issue-with-chirpstack-v4/14578/13
I encountered the problem when 4.0.0 was latest, but unfortunately 4.0.2 doesn’t solve it for me.