Hi Florian,
Adding `SVC_OXSHIBBOLETH=True` in `settings.py` will mark the installer to deploy `oxshibboleth` container/service, not displaying the sub menu in administration UI.
There are 2 ways to activate SAML sub menu in UI:
1. Add `SAML_ENABLED=True` in `setttings.py` (this will only work in fresh installation)
2. Activate the menu in `Configuration > Organization Configuration > SAML Support` checkbox from administration UI.