Are you sure that you had an updated Windows and Edge before you installed Pro? I still think you have remnants (windows 7?) or really old stuff somewhere.
That is possible, however, just a year ago I installed an brand new SSD on this machine with a clean version of Windows 10, and I am pretty sure that when IE 11 was installed as well.
This seems to be the issue while signing in using Google credentials. Please refer the knowledge article here and try the workaround steps.
Bug: Unable to sign in to ArcGIS Online from ArcGIS Pro using Google credentials