Did you get it sorted out?
First time out with the coil, had similar issues. Come to find out that the place I went to others with other detectors had similar issues.
Partly due to EMI being high that particular day and the fact that the ground was mineralized with who knows what. It was a school sports field.
Getting falsing etc. and every item I thought was good was trash. Apparently the mineralization was similar to a beach I hunted with black magnetic sands, it was causing a wrap around effect, loss of depth.
Good targets ID'ing low into iron numbers, iron in the 80's. I went to other spots and the Impact and the 7" coil was fine proved there was no issue with the coil. Went back to that schoolyard about a month later, EMI was down, the ground still gave me problems, found a few coins, junk, then gave up on the place. This school sports field is the only one that gave me these problems. If I remember correctly did try a DD coil there, saw little improvement. Will add that I was still a newbie using the Impact at that time. Now this is just a thought, computers have quirks, since there is a processor in the Impact, maybe, just maybe doing a factory re-set may cure your problem? When my wife's Windows computer acts up, always tell her to stop complaining and do a restart. usually solves the problem. I run a Linux distribution OS on my computer, really never have issues.
