PANS accuracy could be improved

I tested the PANS ranging with 1 tag and 1 anchor.
I received a bit of inaccuracy e.g. at 250cm distance, the software reported an average of 263.6cm. Max = 268.9cm, Min=258.5cm.
I used the dwm-simple example with the device reporting the distance every second.

I received much better accuracy when using the TWR SS example. Is there any way to tune or calibrate the PANS application?