More data, if it helps:
There’s a setting that I had turned on called omniauth_auto_sign_in_with_provider, which is what directs straight to SSO when you go to the login page instead of the gitlab home page. I turned this back off, so user has the option of signing in with SSO or with local creds.
If I sign in with local creds:
• The first time I click on a file to view, I get redirected to the login page again.
o If I sign in again with local creds, the loading of the file works as expected. And also for all other files I click after that (but I don’t have to go home page and re-authenticate again, it just works).
o If I click on Sign in with SSO, I never get to the file, I always get re-directed to the home page.
I’m not sure why I get re-directed to the authentication page the first time I click on a file regardless of how I’m signed in, but then after that it seems to be handled differently whether you authenticate via SSO or local.