Home Sharing content incomplete in Music app on iPhone and iPad with OS 18.4

Sharing my music library from my MacBook Air to my Apple TV 4K, iPhone 13 mini and iPad Air 9th gen was working fine until I updated the iPad to iPadOS 18.4. All of these devices were running the immediate prior release (macOS 15.3.x, tvOS 18.3.x, iOS 18.3.x, iPadOS 18.3.x) when everything was still working.

After the iPadOS update, the iPad's Music app shows only 60 playlists (roughly a quarter of my collection), and only as a flat list in the Recently Added view. Also, all of my top level playlist folders appear in both the sidebar and All Playlists view, but they are all empty.

Updating the iPhone to iOS 18.4 resulted in these same issues appearing in the Music app on that device. Updating the Apple TV to tvOS 18.4 did not create any issues there, with music via home sharing still working just fine.

Updating the MacBook Air to macOS 15.4 didn't help. Turning off Mac home sharing, restarting, and signing back in didn't help. Signing out of home sharing on the iPad, restarting, and signing back in didn't help. Doing the same on the iPhone didn't help.

FWIW, the list of playlists in Recently Added matches the order of those playlists as displayed in Music on the Mac, except with the folder hierarchy flattened. It's as though the software picked up all the playlists in the first two top level playlist folders (out of 13 total), plus the first subfolder of the third top level playlist folder, and then just stopped.

I welcome any thoughts or suggestions.