Height estimation error

We have problems flying offboard using Vison, where we are not able to takeoff at a predefined altitude (we are flying indoor).
Then I investigated a little be more and hence I did a test (here the result: https://logs.px4.io/plot_app?log=be6f9b48-5a1e-446b-af7f-065ec7536cb8) where the drone was on a desk, the motors weren’t powered and manually I moved the drone up and down. I compared the ekf2 estimation with the ranger finder reading and something is wrong.
The range sensor works fine but the EKF2 local position NED (z-axis) is wrong.
Can anyone help me understand where I am wrong or if there is a software problem?
Thanks in advance, Massimo

The main params config for the ekf2 filter are the following:

This may or may not be relevant to your issue.