This might be better suited to the general support area but I am not sure when this started so I will post it here. Currently on build 1160. Upon selecting certain albums that are in my library then scrolling down the page to the Selected Albums area I see occasional listings for other albums that Roon apparently thinks are also in my library and are not. For example I selected the album Appetite for Destruction by Guns N’ Roses from my library then scroll down and see this
Notice that Toys in The Attic by Aerosmith is shown as in my library when it is not. If I click on it I get this
This is just one example. I have run across others though just a few so far. I believe I had added this album at one time and removed it. I had issues with old tags resurfacing during Arc beta-testing so it could be related.