I am not sure if this has been logged.
It would appear the Composer Performer toggle has been removed.
The upshot in some cases is that albums are in the library but ignored in the Artist view.
One example is Wilhelm Kempff , who has recordings of Bach transcriptions, it looks like he is being treated as a Composer and the 30+ albums as a performer don’t show just 4. Although some do , it’s not even consistent
The Discography shows a lot more in Tidal but if if apply the My Library button I am down to 3 albums, JRiver shows me 39 !
I assume some logic has been applied to get around the Artist tag being set to Composer in much of the older Classical catalogs, since the tag for Composer is not there
Leonard Bernstein is another example