Inconsistency in local metadata settings

Server Version#: 1.43.4.10903 (Windows 11)
Player Version#: 4.160.0
I have a classical music library (“Classical Music”) that points to one folder, a separate music library (“Music”) for everything else that points to a different folder, and then a third (“All Music”) library that includes both folders. Despite both having the same settings, “All Music” shows local metadata, but “Music” does not. I picked one of the affected albums and tried refreshing metadata, but it doesn’t make a difference.

How exactly did you go about “including both folders”?
Did you add both folders individually on the “Add Folders” tab, or did you point the library to the parent folder of “Classical…” and “Music”?
If the latter, you did it wrong.

Side note: the file properties tab of Windows file explorer is inadequate for viewing and editing music metadata. It doesn’t show the “Album Artist” field, which is very important in Plex.
You should rather use a dedicated metadata editor, like e.g. mp3tag

I added both folders individually. And here’s the mp3tag view of that track:

How is the folder structure looking like for this album?
Even compilations and soundtrack albums must follow the structure described in here: https://support.plex.tv/articles/200265296-adding-music-media-from-folders/
No additional folder levels, no fewer folder levels.

And even more importantly:

  1. All the tracks of a particular album must have identical content in their Album Artist tags. (Content of the regular Artist tag can be different.)
  2. All the albums stored inside a certain artist folder must be tagged with an identical Album Artist.

This means that you must NOT use a subfolder for all the soundtrack albums.

This particular album must also NOT be stored inside an artist folder named “Various Artists”, because it uses “Hans Zimmer” as Album Artist.

Interesting - I have all my soundtrack albums in a folder titles “Soundtrack Music”, with each album listed by title. What’s strange is that my “All Music” library has no problem with this, but the “Music” library is inventing this “Hans Zimmer & Steve Mazzaro” artist. And using the Blade Runner 2049 album as an example, all the tracks have the same Album Artist: Hans Zimmer. One other thing of note - I just recently created the “All Music” library, but the “Music” library is quite old. Perhaps there’s a setting that never got set correctly, and it’s just not respecting the local metadata settings.

And I tell it is wrong.

Understood, but it doesn’t explain why two libraries with the same configuration, looking at the same files in the same folders, are showing different results, with one of the libraries ignoring the settings to only look at local metadata.

You cannot expect consistent results if you don’t do it correctly.