Brake Controller not releasing

[292BHDSCoachmanMN]

About every 20-30 braking events, my brake controller will not "release" the brakes even though the TV brake is not being pressed(just released). I upgrade the brake controller to a P3 and it's still doing it. So, I went into diagnostics on the brake controller and noticed the stop lamp voltage up to 14 or so when this happens. When normal towing (no braking) it's at 0.4 volts. Is this a stop lamp switch issue or something else potentially? Is the .4 voltage normal during towing? I have verified the wiring is correct on the brake controller.

TV is a 2008 Sierra Denali 6.2

[klrobert]

Sound to me like an issue with the brake light switch on the TV. When this happens, do your brake lights stay on? Since you have eliminated the brake controller, I would think it is either in the trailer brakes or the brake light switch.

[kandl]

Have you verified that the breakaway switch is functioning correctly? Not shorted?

[292BHDSCoachmanMN]

Additional info: when this happened I observed the tail lights - they were not activated which leads me to believe it might be something on the trailer side and not the TV side.