PMW3901 stops sending valid data

Hi ,

I am using the PMW3901 Optical Flow Sensor Breakout, it seems everything is working fine but after a few hours/days the quality decreases (for the same surface from 150-200 to ~50) and the flow is around 0 (±1) when i move the drone.
I am using the stm32 Bluepill with SPI communication, the problem if fixed after I restart the board and the sensor.

Any ideas?