OpenID Connect to Nextcloud not working (v3.3.6)

[himpierre]

Hello!

Is nextcloud openid connect supposed to work? I constantly get 404 from greenlight. The log says:

D, [2024-07-26T14:29:47.777511 #1] DEBUG -- omniauth: (openid_connect) Request phase initiated. E, [2024-07-26T14:29:47.963790 #1] ERROR -- omniauth: (openid_connect) Authentication failure! Not Found: OpenIDConnect::Discovery::DiscoveryFailed, Not Found
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Nextcloud OIDC Provider Settings:
Redirect URI: Greenlight URL
Client Identifier: xxx -> Copied to Greenlight .env OPENID_CONNECT_CLIENT_ID
Secret: xxx -> Copied to Greenlight .env OPENID_CONNECT_CLIENT_SECRET
Signing Algorithm: RS256
Type: confidential
Flows: Code Authorization Flow
Dynamic Client Registration: disabled

When I do curl the OPENID_CONNECT_ISSUER=https://mydomain/.well-known/openid-configuration I see all the fancy stuff.

That's basically it. Any help really appreciated.
cheers!