itunes not syncing correctly with external HD library

I recently bought a new laptop and am now running the latest version of itunes on windows 11. I go into edit/preferences/advanced and tell itunes to use my external HD library but nothing happens, and every time I re-open itunes it reverts back to the default c/users folder. Holding down ‘shift’ whilst opening itunes opens the ‘select library’ window but there is no option to actually ‘select’ the folder on my external HD - only open it which does nothing. The only way I can get the library onto itunes is via file/add folder to library, but this takes forever, makes a copy on my laptop HD and doesn’t import my unchecked-checked songs status or dates files were originally added to itunes. This is vital as I have a large library with many unticked songs to make room on my my ipod touch. Everything still works fine on my old laptop running windows 7 but it’s a potato now and reverting to that older version of itunes didn’t work either. Please help as I’m at my wits end.