If I play a full album in ARC (so that Roon Radio starts at the end, to know it’s really completed), the play count of the last song of the album isn’t updated. I see it as played (and not skipped) in the Queue, but the play count doesn’t change for the last song and that specific song isn’t scrobbled on Last.fm either. For all the other songs but the last, everything is fine.
Not sure if there is ongoing discussion elsewhere about this issue - this is all I’ve found, but I still have this problem now - noticed heaps of albums recently where I’ve listened to the whole thing on ARC and the last track of the album hasn’t incremented play counts when I look later.