That’s consistent with what I’ve been seeing Ged. Build 55 of 1.1 has now been released and includes better handling of duplicates after deletion of files. Let’s see if that has affected this behaviour.
Are you using an organised folder ? I rip into an organised folder and then copy to a watched folder and move to a backup. Sometimes I seem to be missing an entire album after a merge. When that happens I have found the files in the organised folder under a previously merged album name, so check that out before re-ripping if it should happen to you. I am now closing Roon when I copy and shift files, cleaning up the library after moving files from the organised folder and doing all my merging on albums in watched folders. I figure that should minimise the scope for problems to arise.
Also I think @REShaman and @Rugby are onto something in this thread:
It may help to let Roon thoroughly digest new tracks before invoking any operation on them.