In our coach a bedroom roof air vent blows directly down on the rear A/C temp sensor (thermistor) causing the A/C to prematurely think the bedroom is cooled down to set point.
To keep the temp sensor out of the cold air flow, we covered the sensor with about a 2" deep bottom of a plastic cup. To allow some room air to reach the sensor, a small part of the bottom (facing the floor) of the cup is removed.
We thought about relocating the bedroom temp sensor out of the air flow, but decided our homemade cover solution is good enough. This sensor is wired to the rear A/C.
When a roof A/C has a temp senor plugged in, it uses that sensor to turn that A/C on and off. When a roof A/C does not have a sensor plugged in (like our front A/C), the default is to use the temp sensor built into the wall thermostat. More than one A/C can be controlled by the same temp sensor.
Temperature sensors, location, location, location. In commercial buildings we often put them behind the office door. Air can't blow on them, and some fool can't park a laser printer or PC under it.