Unrelated admin group is created instead of adding user to the nextcloud administrators group

I am currently using Authentik with the OIDC provider backend. I already tried to pass groups as the simple array:

["admin"]

and using the object:

[{"gid": "admin", "displayName": "admin"}]

The payload that sent is:

{
    "name": "some user name",
    "groups": [
        {
            "displayName": "admin",
            "gid": "admin"
        }
    ],
    "quota": "200 GB",
    "user_id": "some user id"
}

My OIDC is configured as follows:

Start by reproducing the OIDC login with the provided groups payload and configuration, then trace how the gid and displayName values are mapped to Nextcloud groups. Done means the existing Nextcloud administrators group is used instead of creating an unrelated admin group, with the behavior covered by a regression test.