Switch 6 randomly sending wrong commands to VLT2

Hi guys,

I bought a Voicelive Touch 2 and a Switch 6 (both second hand) and I've been using the Switch in Custom Mode (with the first six effects assigned to each footswitch). But sometimes the commands from the Switch 6 will go nuts and turn the wrong effects (diferent then the assigned ones). When this happens, I reinsert the TRS on both ends until it gets back to the proper assigned functions.

Can this be a bad TRS cable thing? Or could it be because I have a malfunction Switch 6 unit? How should I get it fixed? I can't have this happening in the middle of a concert... Does anyone have any guess on where the problem lies?

Thanks in advance