Just set up the towing. Brake gain set at 6.0 (as in my 2017). Initially checked by manually squeezing the brake controller levers. Good brakes. Afterwards, no braking whether manually or with the truck brakes.

 

I'm assuming you have this fixed by now. But is it covered under the recall? My brakes would work a few miles and quit. They reflashed it and I haven't had any more issues.