If you are missing a folder in Quick Access or if you are trying to Pin to Quick access a item on your Windows 11 computer and that is not showing up follow these steps.
Go to %AppData%\Microsoft\Windows\Recent\AutomaticDestinations
In this folder you will find the file f01b4d95cf55d32a.automaticDestinations-ms
Move that file to another folder as a backup
Then after about 1 minute your Quick Access list will be updated and should show all of the items. And you should now be able to add new Quick Access items that you want.
If all goes well then delete the file f01b4d95cf55d32a.automaticDestinations-ms that your moved to another location since you do not need your backup copy.
This also helps with issues after adding or removing folder redirection in OneDrive.