macos – Big Sur – unusable UI when waking from a long sleep with sluggish and flickering redraws

After waking from a long sleep Big Sur’s UI is practically unusable. It’s slow, apps don’t draw properly, there’s lots of redraws happening. It’s like garbage collection isn’t happening for UI elements.

Examples include:

  • Various things won’t draw unless you scroll over it with the mouse
  • When mousing over it, only part of it draws
  • Animations flicker (badly), like activating the hidden dock
  • If the menu bar is usually hidden, it’s completely blurred when mousing over it
  • Text boxes don’t appear properly. There’s no blinking cursor (even though I can type into it)
  • app switching can’t be focused properly via the keyboard. Mousing over it sort of works. But the app doesn’t actually come to the foreground… again unless you can somehow scroll over it.

I’ve tried the following unsuccessfully

  1. Enabling/Disabling Touch ID
  2. Putting the computer to sleep and waking it back up again (even the login screen is confused, still drawing logged in content in part)
  3. Logging out and back in again
  4. Quitting all apps.
  5. Adding new desktop screens
  6. Unplugging a USB hard-drive, putting the computer to sleep and awaking again

The only thing that works which I’d like to avoid is to restart the machine. The UI is usable enough to show the Apple menu and select Restart…, even though the menu highlighting is flakey.

NB: I’ve tried all the suggested solutions at Big Sur – unable to focus any app or make mouse/keyboard inputs after waking from sleep?. Whilst it seems like a possible duplicate question, the accepted answer has had no effect.