What is killing the weight sensor HX711 when uploading new code ???

I'm trying to build a simple digital scale with HX711 sensor and a Teensy 3.1 (I tried with arduino also and the result is the same)

I use the libraries from https://github.com/bogde/HX711 The test code works at the beginning, but if I try to upload code changes (for calibration) while the sensor is connected and powered up, the sensor ports will die after few uploads. The same happened with both ports A and B of HX711.

Configuration as follow: Teensy (Arduino) connected through USB

Weight bar is connected to the HX711 sensor. The HX711 is connected for power to Teensy (Arduino) GND and 3.3V (5V) and the signals to A0, A1.

A more stable configuration I have if I power the HX711 externally (common ground with the controller), but I still have to shut down the external power if I want to upload code into the controller, otherwise the HX711 ports dies sooner or later.

There are some transient power surges ? :smiling_imp: that goes on pins when the controller gets programmed??

Any ideas??