I have encountered the 913 nightmare update, and the following worked for me..

W11 laptop - PLAY 1 stereo pair

S2 APP Will not recognise any drive or storage other than that which is on “C” and in MUSIC folder.

All shares and permissions have to be given for APP to read etc.

Save your mp3s all in “C” Music and grant all permissions.  Then add as to Music library as usual            It has worked for me

Like so many others I cursed the recent update that removed my library share settings  (913 nightmare).

Good luck with this.