In an Explorer window, my Windows 10 "Quick Access" menu does not take new pins or remove existing ones based on folder actions initiated via the right-click menus.
For example, if I right click "Folder XYZ" in an Explorer window, select "Pin to Quick Access" - it does not get added to the Quick Access menu.
If I right click an item in the Quick Access menu, select "Unpin from Quick Access" - it does not get removed from the Quick Access menu.
So the old "Favourites" functionality is gone. There appears to be zero control on this replacement menu.