3 things, if you are loosing connection with wifi then sometimes if you push a fader up on the ipad it might not instantly move the faders on the desk, there may be a few seconds delay and then the faders move. If this is the case then it is due to bad wifi reception in the venue and not anything to do with the console. Wifi doesn’t work everywhere believe me.
The second thing could be accidental channel ganging this will make faders follow each other and move on their own.
Thirdly did you have your ssid hidden and network password protected? Someone could have been messing with you 
