Track titles missing from music albums on my iPhone

All my albums from 15 years of adding music to iTunes now have this odd thing where the titles of album tracks are blank when you open an album in Music on my iPhone but when you hit play the track is visible and when you tap on the playing track you get the tracklist displayed with the titles showing.

This only happened for some reason on all the many albums I had added to iTunes/Music up to about a year or so ago - anything I upload now displays correctly.

I've done all the stuff making sure Work & Movement are empty and unticked, I have album artist selected for every track and I'm stumped as to why this has happened or why to fix it. I prefer my own files to be on my phone rather than streaming and have a 500gb IPhone with 40000+ tracks on it and this has affected at least 3 quarters of those tracks so it's very frustrating.

I've attached examples below - the first is when you open an album (ignore the track from another album I was playing last in that photo), the second when you play the first track and the third when you tap on the playing track.

[Re-Titled by Moderator]