Long story short:
On my iMac (where my music library is kept, running Catalina), I am unable to get Home Sharing for my music to work.
My MacBook on the same network (also on Catalina, signed into same iCloud account) won’t show the iMac’s music library (or the required little downward arrow next to “Library” in Music).
A bit longer:
I have tried signing out of and into my iCloud account (my registered iTunes account), I have tried de- and re-authorizing my Macs, I have re-started my Macs several times - no luck there.
The weird thing is that the “Media Sharing” checkbox in System Preferencens -> Sharing -> Media Sharing stays greyed out (whatever I do).
I have tried simply selecting the “Home sharing” checkbox in the same preference panel - then the “Media Sharing” box also gets checked and my iMac displays the message along the lines of “Home sharing is now turned on” … but it simply isn’t. The library doesn’t show up on my other Mac on the same network. (Only when I select the “Share media with guests” box, the library suddenly appears on my other Mac - but that’s supposed to happen with only “Home sharing” selected …)
I have no idea what else to try - any advice would be highly appreciated.