I'm on MacOS 11.4 Big Sur and have kept Evernote upgraded. Now on Evernote 10.15.6. Almost every morning, after the machine has been asleep, the window is blank and I get the "Window Not Responding" Keep Waiting or Relaunch message. Clicking Relaunch fixes it but this just seems like someone put a hack in to avoid a serious issue.
I have been getting this behavior since I reinstalled Evernote three months ago.