Need help quad unable to hold altitude with sonar sensor


Just tested my x quad with new downward facing sonar sensor.

I flew the whole flight in loiter, however from the minute it took of, it either ascended or descended and I had to play with the throttle to maintain altitude the whole flight.

To configure I followed the instructions here.

RNGFND_MAX_CM was set to 700 cm.

Can someone take a look at my log file? I’m not sure but looking at the log for rfnd dist1 shows some crazy ups and downs, maybe my sensor is broken?

my log