Hi all I've been to Burnham on sea beach today with my Ace 250, spent about an hour and a half there and found 14 p 6 nails and 2 screws in that order

I walked from the peir towards Brean up as far as the wooden light house / lookout thing.
but the Ace 250 cept giving fulse signals and would throw a wobbley from time to time.
anyone know why?
Steve