I'm having exactly the same issue after updating MyDrive Connect this morning. I also had some difficulty loging into my TomTom account on the web. Just got a blank page after loging in and had to manually refresh the page.
I wonder if it's an issue with their user authentication servers rather than a MyDrive connect problem.
Hopefully, TomTom might be monitoring and let us know soon.
Had the same problem.
Delete MyDrive Connect and reinstall (takes a couple of minutes).
All now working fine.
Seems that TT screwed somthing up as a 'routine maintenance' screen flash briefly.