Yeah! I don't think it's a weird issue though, it's just hard to describe. I haven't taken the shell off yet, so I'm not sure if it's a design problem or a material problem, but there's just too much lateral tilt on the buttons, which causes friction on the little support legs that this type of button have.
I've actually experimented with some tape and discovered that if you can pull a button over a bit towards the side with the legs, it doesn't tilt as much when you press on the opposite edge and the problem goes away.
The tape isn't exactly a permanent solution though, but it's a start. GPD have mostly done an outstanding job with the Win 2, but this sort of thing is a real problem on this kind of device. It's kind of annoying that there isn't a replacement part or a recommendation from GPD to improve this, but there you go.