Strange field

[Geo]

Hi. Before few days i checked a place with a lrl to see if there are fields from hidden objects. There is a place where when i go near it (about 3 x 1 meter) with my MFD (magnetic field detector) and from east to west the lrl beeps continuously without the need to move it right and left. When i go from west to east it gives some beeps. From south to north or from north to south don't give me any beep.
Also from east to west i take beeps even i will turn the sensitivity low. With normal sensitivity it beeps as at one video of Morgan where his PD don't need moving.

Any idea??????

Regards