You should not be getting the falsing, especially at Sensitvity 14!! I hunt 28-32 in Semi Auto all the time and not too sure your soil is much different than the acidic jersey sandy loam soil.
I just got the new SE Pro coil for my XS, main reason was, I needed a new coil for awhile , since my 8 inch ML coils were falsing, due to heavy underbrush use over the years, thorn hits in the cable, etc. My stock coil was still fairly decent but that too was starting to false more than I liked( 8 years of heavy use).
Reasons: #1 Coil/Coil Cable bad to some degree
#2 Undo and then retighten the connector of the coil at the unit
#3 Did it come with another coil? if so try it.
#4 I heard someone say, although I have not have it happen, that the battery pack, especially the rechargeable ones can cause it, but I find that a stretch.
#5 I doubt it is the unit itself but perhaps.
#6 If it came with the Sunray Probe, that could be the culprit.
I literally had to hit my coil against a tree sometimes to stop the falsing, and LOL, it worked. Since I got the new SE Pro Coil, there has been no falsing on my 8 year old XS.......
OH, one other suggestion, if you have FAST ON turn it OFF and see if that helps..........I never use FAST ON, to many high tone readings (false ones)
Don