cannot pin folder to navigation panel Windows 11

"In Windows 11, I cannot pin folders to the navigation pane (left sidebar) in File Explorer. When I try to drag a folder to the sidebar, I get a 'no drop' icon and nothing happens. Right-clicking and selecting 'Pin to Quick Access' only adds the folder to the Home screen, not to the sidebar as a pinned item. I have tried resetting File Explorer via Registry (NavigationPaneViewModes), running sfc /scannow (no errors found), and disabling Fast Startup — nothing helped. Other Windows 11 computers work fine. My PC is ASUS ProArt Studiobook running Windows 11 latest update."