Apple Devices on Windows 11 can't open Apple Music library

Non 'sync' between Apple Device and Apple Music on Windows 11. PC: Windows 11 25H2. Phone: iPhone12.

Did have Apple Music (and my library via App) on my Windows 11 Laptop. So now putting it on my Windows PC desktop Win 11 25H2 i7 8th Gen 1Tb SSD 16Gb RAM. Installed Apple Music from MS store. Logged in and can see my exiisting library. Music\ on PC in C:\user\ME\Music\Apple Music\Media (default library folder). Then installed Apple Device and can see AND connect to my iPhone12 ok. When I go to Music it says Open Apple Music it opens Apple Music OK. But it says "The Apple Music library could not be opened." To fix this open the Apple Music App Thats what I did Apple Device opened Apple Music. And even when opened it still says it can't see the Library? ! I have installed iCloud in case Apple Music and Apple Devices need this. iCloud is working re photos etc. If I add an M4a using add Folder in Apple Music it doesn't seem to do it and I Apple Devices connected to my iphone 12 still says the Apple Music library could not be opened. It worked on my laptop which was also Win 11 25H2. I really need some Help/advice please I am not really an Apple user yet. Exploring using an iphone and now with my Win 11 PC. Hope there is enough INFo