Check the signal quality on the i2c interface, it must meet the signal strength requirements. For example, for Holybro Pixhawk it is a level of 3.3 V.
The waveform must be correct without peak emissions along the rise and fall fronts.
A suitable airspeed sensor that is recommended by Arduplane, such as Holybro Digital Air Speed Sensor,Digital Air Speed Sensor (holybro.com). If you have a 5 V sensor then it is better to use the PCA9306 dual bidirectional I2C−bus voltage−level translator.
