After a server migration I expirienced a somehow similar behaviour. After the cloudron restored from the backup penpot OIDC didn't work.
penpot package version: 1.7.0
Frontend said: "Authentifizierungsanbieter ist nicht konfiguriert."
On the backend: "E app.http.errors - hint="restriction error", data={:type :restriction, :code :provider-not-configured, :provider :oidc, :hint "provider not configured“}"
I did the following diagnostics:
I checked OIDC login on other apps (e.g. gitlab) -> worked as expected.
I checked curl -v https://my.mydomain.de/.well-known/openid-configuration -> it answered correctly
cloudron-support —troubleshoot -> said all checks [OK]
I freshly installed another instance on the same machine but different domain. As a regression to 1.1 was no Option -> same error
I double checked DNS entries. -> same error
I renewed the password of the accounts setup in penpot -> same error
Now after about 24h after the restore I tried again a fresh install -> it worked
Returned to the previous instance –> It all of a sudden worked.
Solution: Time is a healer…
This is realy very astonishing and I feel lucky, but it is not very reliable and now brings up questions how to secure the designwork of me and others when working with penpot. Unfortunatly I have no time left to further investigate, but it seems that OIDC & penpot have issue after restoring of cloudron...