SAML authentication

Is it possible that SSO is broken when the browser is Safari? I’ve been going back and forth with Support about one user who can’t log in, they want videos, screen shots, a browser webdev tool recording, etc.. I decided to recreate most of the screen shots using my own computer and Safari, knowing the user in question was using Safari, and what do you know, I get the same SSO failure as shown below. However, flip back to Firefox, log out, clear cookies, start fresh, and it works fine. Seems weird that it would be browser specific but now I can reproduce it.