I have the same issue an my guess is that its some kind of electrostatic buildup problem. Seems to me like blowing (with your mouth) into the keyboard (in between the keys) often fixes the problem. I had a similar issue with my Razer Black Adder Chroma mouse, where it would not register clicks / double click and gamers figured out that blowing into it helps because the moisture in the air does something to the static charge. It immediately clicked that the problem might be similar, and usually when I try it helps, though sometimes I need to try for a while (that’s why I’m not sure if it isn’t mechanical or something else, as I need to lift the laptop and move it etc.)
The fact that here and elsewhere people describe similar issue, similar keys (D, backspace & enter most severe) also suggests the issue is not some random hw or sw failure.
I came looking on the forum because blowing into the keyboard almost every time I take my laptop away from my work station is lame and annoying. 