I've had a GR for a couple months now and been out with it a few times.
The first thing I saw was your threshold at 35. I usually run at 17-20. At 25 or more, I know I can't hear the faint stuff anymore.
Running your sensitivity at 69 doesn't seem like too much, but in some conditions, you may have to turn it down more. Try it at 50 and see if things improve for you.
When I was trying to run with too much sensitivity, I would get a lot more false signals and the readout would go from 1-4 to 98-99 on ground mineralization. Once I started running the 'gain' lower, I had less issues and more stability.
I haven't played much with some of the other features, so I can't be of much help there.
Good Luck !!
Luke