Sounds like classic antenna delay calibration issues to me.
Set 3 up in a triangle. Measure all 3 sides. Work out the amount you would need to add/subtract from each unit to make all the results correct. Set the appropriate antenna delay on each unit. Repeat until all units are calibrated.
You should now get the correct values.
Also on the xtal trim settings make sure you’ve let everything warm up and things aren’t sitting in a strong air current before doing this, it can be very temperature sensitive.