S6 losing input Gain control

Our studio has an S6, and recently (among all the other teething issues) random tracks on Pro Tools have been losing gain controls on the surface. We can get level in, then all of a sudden all the input controls won't work or reflect what the controls say in Pro Tools. If you change control type e.g to pan and back to input, the display is blank.
The problem moves when banking, so it's not a module issue.


Has anyone else experienced this? Is there a way to fix the problem without deleting/duplicating the tracks?

S6 losing input Gain control