Self managed - Grist/Google SAML/Traefik Need help with setup

For one, this post shares a setup that works: A template for self-hosting Grist with traefik and docker compose - #25 by yala1

The network and traefik configuration seem the most relevant, given your symptoms.

For debugging, I would suggest looking at the Network tab of the console, and logging in again. When examining the requests and responses, I’d expect the first visit to Grist to set a session cookie (grist_sid) in the response, then after redirection, the browser should send this cookie back to Grist in the request.

BTW, I am not familiar with GRIST_FORCE_SECURE_COOKIES variable – I am not sure it’s a thing.