Too Many Redirects Jellyfin Cloudflare
So a friend of mine runs Jellyfin through his Cloudflare tunnel, despite being against TOS.
He has his site break all of the sudden with “no changes on his end” and it was a simple fix. I had to show him how to disable HTTPS re-writes so the error would cease. He had some of the HTTPS features enabled, and Flexible SSL but wasn’t using HTTPS on his Jellyfin container (TrueNAS App).

Turning off “Always Use HTTPS” when not using HTTPS is a good idea.