Little weird: Power button does shutdown and reset randomly

[Ombiax]

Hi,
So I am working on a project right now and we have a machine, which does a couple of important things.
The problem is, we installed a button which should normally just reset the PC. Just like a reset button should do.
Sometimes it resets the PC and sometimes it shuts down the PC. And it's random (at least I didn't see a pattern).

It's just a tiny PC inside of a machine and we did all the wiring ourself and it should all be correctly wired.
Why is it, that it sometimes resets and sometimes shuts down the PC. I could really need some help with it, because I have to get it done in 2 days.

Thanks in advance.

[OddOod]

To be clear, you *know* it's the button? You've unplugged the button and the behavior goes away?
What kind of machine? I have a thought

[OddOod]

Knowing literally nothing about this:
If it really is the button that's doing it, I'm thinking that this is a machine that has a big honking motor in it and the wire for the button is long. What's happening is the wire for the button is slicing through the magnetic flux of the motor and inducing a charge which the mobo senses as a short across the pins which triggers a software shutdown/reboot