Catalina Music app freezes

I’m finding it impossible to keep a music library on my Drobo 5N (firmware 4.1.4-8.120.108863) in macOS Catalina (10.15.4).

The device is mounted via Finder “Locations”, using AFP (e.g., Finder shows the “Server” of a folder as “afp://Dorindo._afpovertcp._tcp.local/Media/Music”).

A variety of file-related actions trigger an app freeze, including moving the library location to the Drobo, modifying music track metadata for files stored on the Drobo, and adding/downloading music.

For example, on a 10.15.2+ system, do the following:

  • In Finder, connect to the Drobo
  • Open Music; optionally, hold down ‘option’ and create a new library
  • Ensure the setting “copy files to Music Media folder” is unchecked
  • Add an mp3 file stored on the Drobo to the library
  • Do “Get Info” on the newly-added file and modify a field (e.g., Genre)
  • Upon clicking “OK”, the app freezes

This is a regression: the freeze does not happen in 10.15.1, and I’ve kept my iTunes/Music library on the Drobo for a long time. I assume the Drobo’s implementation of AFP is violating some assumptions made by macOS.