How do you judge the touch pad gets less sensitive?
If I tip on the touch pad at 60°C ambient temperature it has not the same sensitivity as at 25°C. I need to tip harder on the pad. (I have programmed three dim steps which shall be switched through when tipped).
Could you attached the tuner signal here?
There are many factors can make the sensitivity change.
You should to check :
1: if there is air gap between overlay and sensor~
2: If the MCU don't handle the sensor trigger mask in time.
3: Depending on the capacitance touch theory, the signal is only affected by the touch area, not by the force. So if you tip harder on the pad, it triggers, maybe you should check the sensor and overlay.