"You cannot change the music library at this time because the current library is in use by a device. Sign in without connected devices to change your music library.": Workaround

Running Big Sur.

I needed to change libraries today, and got this message. Powered off every iOS device, turned off Sharing in System Preferences. Still got the message.

Was able to bypass by doing the following:

• Turn off Wifi.
• Shut down the machine.
• Power back up.
• Option-click Music
• Select the alternate library in the dialog.
• Re-enable Wifi.

I do hope Apple fixes Music at some point, but until then this seems to work.