I have the same symptom as Donna, which started with a new required login update today (08-04-2020). I've tried the suggestions above short of a roll-back (like Donna), but nothing's worked.
Hi, I'm having exactly the same issue. Was fine yesterday and today this has happened. I have followed all the steps and it changes nothing - other than telling me to login to Xbox (which I don't own). I have also looked for an update that might have caused the problem and cannot find anything that happened in the last 24hrs. I think this might be a sign for me to uninstall and find something else.
I agree it is time to find another puzzle app. Maybe the vendors will see this and make MS fix it or drop them.