So you have two stats for one heat mat? Thermostat probe needs to be between the heat mat and glass outside the tanks hot spot. It sounds like your mixing up the stats with a thermometer that reads the temps.
A thermostat controls the mat's output and should always be used. Mat's don't feel hot. They should feel comfortably warm. The hot spot should be around 90 cool side 80, ambient 80. maybe take some of the substrate out of the hot side and use newspaper or paper towel. that could raise the hot spot.
I don't use a tank a use tubs. So that's the best I can offer.![]()