Does it actually get hot to the touch, in the same amount the controllers report? Or is it just what's shown on the readouts?
If even unloaded operation heats it up that much, then either the temperature sensor is not correctly calibrated, or the motor is not correctly setup in the controller. (phase/hall combination, hall angle/timing, kV, inductance, resistance, number of poles, etc...one or more parameters incorrect).
if you've used multiple different controllers to operate it with the same results on each, with all their different autosetup/learn/etc routines, it's more likely that the temperature sensor itself is either faulty or not the type the controllers are expecting.