Failed to provision user

Hi,

I have an existing Nextcloud with users already created from LDAP. I'm using Authelia for SSO, and wanting to login through Authelia and it bring up the existing users Files, Mail, etc. (Not create a new user).

I'm using the mappings-id setting for user_oidc to match the same one LDAP uses, and I also have auto_provision = false in config.php (To let LDAP take user creation). It always gives me the error below.
I've tried every setting for mappings-id as well (preferred_username, uid, mail, etc).

"Access Forbidden"
Failed to provision the user

I can't see to find any log files or where to start debugging this. I have found another user that had the same issue (https://github.com/nextcloud/user_oidc/issues/869) and set the mappings-id for users to preferred_username but that doesn't do anything for me.
If I take auto_provision = false out of Nextcloud then it will work, but it creates a totally new user in Nextcloud and doesn't use the existing user from LDAP.
It seems if auto_provision = false is set in Nextcloud then nothing will work to even login, and always gives the "Failed to provision the user" error.

I have also unchecked "Use unique user ID" box and tried with it. It has no difference. This is on user_oidc: 6.0.0 and user_oidc: 5.0.3

Any help would be much appreciated. Thank you

The report names config.php and the user_oidc mappings-id and auto_provision settings; start by reproducing the login with LDAP users and comparing those configurations. Check the available Nextcloud/user_oidc diagnostics around the “Failed to provision the user” response. Done means an existing LDAP user can log in through Authelia without a duplicate account being created.