Office 365 Not Connecting

Trying to set up Office365 Email on Mailspring produces this bug:

This issue also appears on linux.
I run Mailspring (latest Version) on Windows 10.
I run Mailspring on Ubuntu 18.04 Mailspring version 1.93.1

It appears when I attach more than one Office365 account to Mailspring.
I do clean out browser cache and login via the browser - still same error message