Quick Access "Frequent Folders" Keeps Disappearing on Windows 10 1909

Copy & paste this code into a PowerShell window. If it returns 5000, you've "maxed out" on saved folder views -- the OS has to delete a saved view every time it wants to save another one. Thus some folders seem to keep forgetting their views.

((gp "HKCU:\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\BagMRU").Nodeslots).count

If you've hit 5000, you need to delete saved views by deleting the following two registry keys:

'HKCU\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\BagMRU'
'HKCU\Software\Classes\Local Settings\Software\Microsoft\Windows\Shell\Bags'

Sign out & back in or restart Explorer after deleting these keys.

If you haven't maxed out or after performing the above deletion, you can open Quick Access and use the Apply to Folders option on the same View tab in Folder Options where you found Reset Folders. Quick Access has its own FolderType and thus Apply to Folders will create a "custom" view template that seems to minimize "hiccups" with its unique view.