Stuck on "saving" screen when exiting world (new or old worlds), world will not save, progress lost due to force quit

When exiting any world (new or old), the world will not save, staying perpetually on the screen telling you not to turn off your device while your world is being saved. The world is never saved. Force quit is required, and all progress made on the world is lost. For a new world, this means you are back at spawn with nothing. For an old world, the previous progress is still there, but all new progress is lost. Has been happening since 1.21.111 copper update. Running Windows 10 on PC.