I am wondering how is the Z axis value being calculated? I stream the data to my laptop, the X & Y axis values are good enough. However, the z value sometimes is weird. I auto-positioned 4 anchors and I set the z value of each anchor by using a laser measurer to get the height.
In order to improve the Z accuracy, I would recommend to set the anchors at different height. For example, with 4 anchors, maybe set 2 anchors at 2.80 meters and 2 others at 1.80m if possible. This will increase the granularity of the Z scale.