Ek3 z source problem

Hi,
I want to use LiDAR(rangefinder) for EK3 Z SOURCE.

My settings…
・ EK3_RNG_USE_HGT = -1
・ EK3_SRC1_POSZ = 2

However, CTUN.ALT and CTUN.SALT data are different.
I want to use only LiDAR for height because the floor is flat in an air conditioned room.
The accuracy of the BAROMETER is poor.