I’m honestly not sure. Frankly, I don’t see how it could be an issue with any of the other components when the board worked fine upon arrival. So unless there’s something that’s slowly warping the mainboard or the heatsink assembly over time, the only potential culprits are the board itself or the heatsink.
I’m pretty damn sure the deck isn’t warped. However, I will say that I have observed that the body has a slight bend depth-wise. That may have something to do with it.