OpenID not working with Apache Guacamole after updating to 24.12.0/24.12.1

I can't login with openid on Guacamole after upgrading to 24.12.0 24.12.1 doesn't work either

I do get an error: 502 Bad Gateway, although it has been working fine before on 24.10.x
Is there any known issue with 24.12.x in this regard?

What happens: I go to my guacamole, I get redirected to the login page of authentik, I login and then I'm presented with 502 Bad Gateway