I have one, and sometimes mine does that as well. Like, turn sensitivity waaaaaaay down, in Park1, and it’s chirping like a nest full of hungry baby birds! I consulted with my metal detecting friend in town, and he suggested that perhaps it does it when the charge gets low. i didnt have any better ideas (tried moving frequencies, detecting in a different area, etc, but nothing worked) so I just quit for the day and brought it in to charge. Once it was full again, it was smooth sailing. the weirdest part is that I’ll be hunting an area, and it will be totally fine, and then suddenly it’ll just flip the eff out. So, I wouldn’t imagine that suddenly EMI is rampant. But hey? What the hell do I know? I’m still pretty new to this. 😀 Good luck! I hope this helps! If not, I’d love to know if you have another hypothesis!