Used twice Gladiator Bestop Trail cover p/n 8105001 . Great protection for the cab when the tops are removed and truck is parked. $130 plus shipping from Massachusetts.
I had the same issue after I plugged in my brake controller today. I unplugged it as you did and both ess and sway control lights/warnings went away. There must be an issue with how those systems are wired through the trailer braking/lighting wiring hopefully Jeep is aware and there will be a fix.