Hi @karamatic34
Welcome to the Auth0 Community.
I think the issue here is that you have most likely populated the allowed logout url at application level. The system cannot find the setting unless you specify the client_id as part of the logout redirect.
If you do not plan to have an application specific allowed logout url then you will have to populate the allowed logout url at the tenant level which, without the specifying the client_id, the system will be referencing the tenant level setting which I assume is not configured (Auth0 Dashboard > Settings > Advanced).
You can reference our docs on this here https://auth0.com/docs/authenticate/login/logout/redirect-users-after-logout
I hope this helps.
Warm regards.