I think there's a bug in content server, but only in the case where a book has no calibre tags. in that instance, calibre is not stripping out any original tags. the proof of that is that mantano is finding them, after the book has travelled via content server to CC and onwards. I have posted reproducible detail in the main calibre thread. Add a single "test" tag in calibre to the same book & it travels oK, Mantano sees "test", & nothing else.
sorry about the link not working, I did a simple copy & paste?
here's a retry
https://www.mobileread.com/forums/sho...39#post2957639