After rebooting my phone (android 12) all widgets became invisible or started showing "loading"/"widget unavailable" messages. Does anyone know how to solve this?

I have already tried without success to:

1. Re-add the widgets (it has worked with two of the loading widgets, but not with the others)
2. Clear the cache
3. Re-Reboot
4. Uninstall and reinstall the problematic apps

August 20 update: the problem seems to have solved itself by just waiting?
Since I last commented on this post I haven't rebooted my phone or attempted to re-add my widgets. Today I tried again, just to see if something has changed, and they actually loaded after a few seconds. I suppose it's fine like that.