Read about tagging on the wiki. There is a setting in MC to store tags in files or not. Not all file types can store tags.
For me, I struggle with the Wiki due to links to links to links of info and few/no recommendations of what to do depending on what you are trying to accomplish. I read at least four different Wiki entries about tags and still don't understand how the metadata is linked to an audio file, where it is stored, and what determines it's behavior in MC and external files (flac, mp3, etc). I worked with integrating enterprise systems writing and testing use-cases, writing documentation, and teaching users for Oracle, Metaphase, part number systems, tech manufacturing data collection systems for process data, data analysis software, etc, etc and am used to looking at these things but MC wiki articles just baffle me and make me feel stupid. That is why I find the forum so much more useful for solving problems. The settings for tags are at the default (I don't remember ever changing). Attached pic shows what I have.
I've invested at least 8 hours in reading wikis, other postings, cloning libraries, syncing libraries, creating new libraries, and have basically gotten nowhere. IDK what to do. It seems that with all the capability in MC that there should be some straight-forward methodology for getting playlists, ratings, tags from a library on one PC migrated to a local library on another.