Gitlab login with own gitlab not working

My version of HedgeDoc is: 1.10.5

What I expected to happen:

clicking on login with gitlab would send me to my self hosted gitlab

What actually happened:

Instead, I get forwarded to gitlab.com.

I already tried:

I made sure that everything is configured as in the guide at https://docs.hedgedoc.org/guides/auth/gitlab-self-hosted/ and gone over it many times. I simply can’t find the problem.

This is my docker compose:

services: database: image: postgres:17.7-alpine environment: - POSTGRES_USER=hedgedoc - POSTGRES_PASSWORD=secret - POSTGRES_DB=hedgedoc volumes: - database:/var/lib/postgresql/data restart: always app: # Make sure to use the latest release from https://hedgedoc.org/latest-release image: quay.io/hedgedoc/hedgedoc:1.10.5 environment: - CMD_DB_URL=postgres://hedgedoc:secret@database:5432/hedgedoc - CMD_DOMAIN=my.domain.de - CMD_URL_ADDPORT=false - CMD_PROTOCOL_USESSL=true - CDM_GITLAB_BASEURL=https://my.domain.de/ - CMD_GITLAB_CLIENTID=xxx - CMD_GITLAB_CLIENTSECRET=xxx - CMD_GITLAB_SCOPE=read_user - CMD_ALLOW_ANONYMOUS=false - CMD_ENABLE_UPLOADS=registered - CMD_ALLOW_EMAIL_REGISTER=false volumes: - uploads:/hedgedoc/public/uploads ports: - "3000:3000" restart: always depends_on: - database volumes: database: uploads: