What if you made a pin switch in combination with the magnetic switch? Any magnet should work, the magnet from the magnet switch can be replaced with any magnet. Maybe you need a stronger one is all?

I made a solar powered wifi enabled weather station and moisture meter for my garden. The first attempt was my only and it lasted a couple weeks before I noticed the ants liked the heat of the electronics, created a little farm around the box sitting on the ground and then my wife became unhappy about it.

That said I will eventually make another that is elevated from the ground, just haven’t gotten to it yet.