here's the deal: I was traveling from West Virginia back to Nebraska pulling my 36ft 5th wheel. Stopped in Indy for the night, back on the road again in the morning no problems. Stopped in Jamesport, ...
The brakes themselves are fairly simple electrically, so I'd look for a loose wire or possibly a controller problem. Try duplicating the problem in your driveway. If your trailer lights are also going on & off with the brakes, then it's almost certainly a wire problem since the controller doesn't work the lights. Also, look at the controller readout & see if the brake number changes or stays at zero.