Problem: Altitude hold does not use the sonar data

I have set up a sonar on the pixhawk which measures accurately the altitude, following this guide:
copter.ardupilot.com/wiki/common … ix-analog/

However when flying in altitude hold or other modes in which altitude is controlled, the sonar data is not used and altitude with respect to the ground varies. Also the sonar data is not logged: CTUN: SAlt= 0 all the time.

‘sonarrange’ is computed and displayed correctly in MP but at Initial Setup/Optional Hardware/ Sonar , I’m missing the button “enable sonar” which is mission in MP3.3.2

What did I miss? How can I enable the sonar to regulate the altitude?

i’m facing same problem. did you find any solution?