DDJ-GRV6 drum release lever MIDI remapping Rekordbox

I can't seem to be able to remap the MIDI function of the drum release lever. I get the following error:
You cannot change the assignment for this MIDI code.
MIDI IN: 9024
MIDI OUT: 9024

It would be very helpful if remapping this is possible since all other groove circuit buttons are remappable.
Thank you