EKF3 + Marvelmind + Sonar sensor


We are using an indoor flying drone via beacon in Marvel Mind with Pixhawk 2.1.
In addition, connect the four ridar sensors to the I2C port.
I want to recognize left. forward, right directional obstacle and down direction altitude.
However, there is a problem with altitude recognition.
EK3_ALT_SOURCE = 1 (Use Range Finder)
Changed parameters, but do not recognize altitude properly.
However, the distance value is properly represented in the sonarrange item on the DATA -> Status tab.
I would appreciate it if you could give me some tips on how to solve this problem.

Please read the wiki again. EK3_ALT_SOURCE = 1 is not recommended.
But if you insist on using it then update to 4.0.6-rc1 because it contains a critical fix for range finder

Thank you for your advice.
As you said, we succeeded in maintaining the altitude by modifying as shown in wiki.
Thank you very much!