We are experiencing the same issue with two users. User A has Excel crash 75% of the time after clicking on SSO login. No error messages appear in the logs. User B has Excel hanging 30 seconds on startup before crashing. They also experience the issue switching between tabs.
Uninstalling and reinstalling does not resolve the issue. I even cleared all installed files and registry entries related to Anaplan. We are running Windows 10 1909 and Excel 365 1908.