Zoom R24 USB multichannel audio interface no longer recognized

[Johan Vromans <jvromans@squirrel.nl>]

I'm new here so my apologies if I'm asking questions at the wrong place.
Someone told me this could be a regression in ALSA.

I'm running Fedora and have used a Zoom R24 as a USB multichannel audio
interface (8-in/2-out) for many years.

Recently I upgraded to Fedora 42 and now the device is presented as dumb
2-in/2-out USB audio interface.

"pavucontrol" does not present multi-channel profiles for the device.

The command "alsamixer -c 1" (to select the R24) gives "This device does
not have any controls.".

"qjackctl" also shows 2-in/2-out channels.

I use the device with "ardour" for multi-channel recording but that no
longer works, only 2-in/2-out channels are available.

How can I get the R24 fully functional again?

Thanks,