I'm sorry to hear about the SAML authentication errors you're running into. It looks like you're running into an entitlement issue based on the SAML debug stacktrace visible:
Failed to add entitlement: [user:5394][oid:4165/2020][mask:511]
When I attempt to load the user, I do not see the user, but instead an error:
As such, please submit a support case in your customer group to for in-depth analysis and troubleshooting. If you do not have access to the group, please have your Community Manager add you or submit the case on your behalf.
Let me know if you have any other questions.