NX4 faders are dropping randomly

So I’m not sure where this falls under, we have an NX4 in a venue for a couple of years now, getting reports that “Faders are dropping” Its sounding like the cue list will randomly release as soon as they cycle the fader, the lights will come back on as this is affecting the output. This will happen to multiple faders, being told that on bank 4 this was happening to 1,2,9 below the screen.