Describe the bug
When entering the OIDC Well-known URL for an OpenID OAuth source, it won't automatically configure the endpoint URLs. Instead it prompts a "Bad Request" error and says "This field may not be blank." for every endpoint.

To Reproduce
Steps to reproduce the behavior:

1. Go to 'Directory > Federation and Social login'
2. Click on 'Create > OpenID OAuth Source > Next'
3. Enter your credentials (Name, Slug, Key, Secret and the Well-known URL)
4. Click on 'Finish'
5. See error

Expected behavior
Uppon clicking on 'Finish' authentik should configure the missing endpoints using the Well-known URL.

Screenshots

Version and Deployment:

• authentik version: 2024.2.2
• Deployment: docker-compose

Additional context
I thought, it might have something to do with connectivity and proxy, since we are running authentik behind a corporate proxy. But I can curl the Well-known URL from inside the containers.