if there's a data issue with those dimmers changing the socas around won't solve anything
try this;
console -> first problem dimmer -> lights
if the lights have issues swap the dimmer out for another problem dimmer
what it sounds like to me is that the first in your set of 4 is having a data issue and passing it on to the others, as by your explanation, the attached lights are randomly dimming on and off?
that'd indicate a problem somewhere on the control board
switching to manual mode wouldn't over rule this possibility as it's still accessing the control board and if dimmer #1 is the problem dimmer passing information through it (even a passive dmx loop) could result in the corruption being passed on to the next fixture in line
if you add a moving or LED light into the chain after these 4 dimmers, does it respond properly? that'd be a real easy way to see if it was a control issue being passed through the dimmers, and would likely only result in one being shot as opposed to 4