Originally Posted by Moongrave
If the issue doesn't get resolved soon and you get tried enough to create such a batch file, would you mind sharing it?...
I can certainly do that if needed. But thanks to the work of at least Kolenka and Blorks there is now a fix in the Calibre version 0.8.55 just released.
I have tried this version a few times in the short time it has been available and so far it has worked fine with no "Removing" lines in collections (and the records in the books.db Collections table correct)