No master volume DDJ 1000

Hi,

The master volume on my ddj 1000 has stopped working - does this mean that the knob is broken? it seems fine and is not loose at all. It was previously working but i havent used it for a few months.

things i have tried:

rekordbox 5 & 6 - macoS monteray - neither work - has never worked on this device.

rekordbox 5 macOS big sur - doesn't work - used to work on this device

using the latest firmware 1.12 and the latest audio driver for mac

I also tried adding a midi mapping as per the post below - but when i try to use the learn function the knob isn't detected. other knobs are detected.

https://forums.pioneerdj.com/hc/en-us/community/posts/360067885432-Master-level-volume-no-longer-working-in-Rekordbox-6-0-1

Is there anything else software related that would stop the master volume knob from working?