Update on my situation. This was happening, but my computer needed an update. I'm not a computer person so couldn't tell you if this was relevant. The update was:
2021-01 Cumulative Update Preview for .NET framework 3.5 and 4.8 for Windows 10 Version 2004 for x64 (KB4586876).
Did this update fix the issue? I have no idea. Correlation doesn't equal causation, but it's working now.
Five minutes after I hit "Post reply" it might start messing up again. In that case, I'll talk to you all in five minutes. If not, hopefully I'm G2G.
It was working well for a good 15 to 20 minutes and now it's back to not loading. Yup. Something is wrong with the game.