Cannot see shared library
I have a Mac Mini (M1) and an older MacBook Pro on a WiFi network, with the Mini used mostly as a music player. I typically load music onto the music library on the MacBook Pro (from used CDs I buy on eBay ;) and then import it into the library on the Mac Mini. That way, the two media libraries act as backups for each other. I just upgraded both machines to Monterey (12.3.1), and the "open shared library" item no longer appears as an option in Music on either computer. Both guest sharing and Home sharing are on, and both computers are "authorized" and logged on to the same Apple ID. This used to work fine before updating to Monterey. Any idea what's amiss?
Mac mini 2018 or later