[chaley]

Moonreader gets the tags from inside the book's OPF, not calibre's database. If you use calibre's "send to device" or "save to disk" commands to copy the format to your device then calibre updates the book. If you do anything else, such as copying the book out of the library using calibre sync, then you must update the book yourself before doing the copy. You can do that with the "polish" or the "embed metadata" tools.