Allright, based on other Authelia client configurations I have, I started trial and erroring with Authelia's config for unraid.
I was missing this bit claims_policy: 'default' Which is essential getting it going.
For other people running into this, this is my working config in Authelia
identity_providers:
oidc:
claims_policies:
default:
id_token: ['groups', 'email', 'email_verified', 'alt_emails', 'preferred_username', 'name']
clients:
-
client_id: 'someid'
client_name: UnRAID
client_secret: 'somesecret'
public: false
authorization_policy: two_factor
consent_mode: implicit
redirect_uris:
- 'https://unraid/graphql/api/auth/oidc/callback'
scopes:
- openid
- profile
- email
- groups
token_endpoint_auth_method: client_secret_post
claims_policy: 'default'