Or use Embed Metadata, which is a way of manually applying the same update routines on library books that normally is applied in Send-to-device or Save-to-disk.
It is not that calibre
cannot update metadata. It simply chooses not to, unless you specifically request.
There is no point (usually) in changing the in-library copies of the ebooks*, and this way you can always revert if mysterious potentialities happen.
Any method of
exporting books will update the metadata in the
exported copies -- why else can we edit the fields in calibre's GUI?
* -- but sometimes you do want to. Like if you are hosting the books through calibre2opds or some other tool.