Welcome, join the club!
You are just one of the many many folks who hate the new rigidity of plex music naming requirements.
Just want to confirm, that you do have the music library set to use prefer local metadata ?

if so, and it still isn’t working to your satisfaction, the only real work around is to find a folder organization that is closer to plex’s requirements.
It’s not exactly correct, but plex mostly works with my organization of
/media/audio/MP3/A/Alanis Morissette/2020 - Such Pretty Forks in the Road/01 - Alanis Morissette - Smiling.mp3
/media/audio/AR Verified/0-9/65daysofstatic/2016 - No Man's Sky- Music for an Infinite Universe (disc 1- No Man's Sky- Music for an Infinite Universe)/01 - 65daysofstatic - Monolith.flac
/media/audio/MP3/_Various/2006 - Accession Records, Volume 3 [MP3]/12 - Lights of Euphoria - Emptyness (Accession to Eurphoria mix).mp3
I use mediamonkey too!
here is my (super complex) auto-org template, customize to suit your needs
$left(\\servername\sharename-media\audio\$if(<Quality>,<Quality>\,$upper(<Extension>)\)$if(<Grouping>,_<Grouping>\,$if(<Album Artist>=various artists,_Various\,$if(<Album Artist>,<Album Artist@1>\,<Artist@1>\)$if(<Album Artist>,<Album Artist>\,<Artist>\)))$if(<Album>,$if(<Year>,<Year> - )<Album>\)$if(<Track#>,<Track#:2> - )<Artist> - <Title>,200)
Do note, I use the full Various Artists album artist tag where applicable, but the folder is shortened to _Various
I also use the mediamonkey quality and grouping tags to sort certain collections into their own dedicated folder.
if you have stuff with random quality and grouping tags, you may want to avoid the above template.