Doesn’t bother me at all, I completely understand. I was just using that as reference I go though hundreds of these and some are just bad. That is why I have those ramps replacement parts. To fix the funky ones. The voltage regulator is a bit to hard to solder nicely so I will sell those super cheap one day as proto boards.
But it could be anything, like @jeff said, mosfets touching, stray solder, unplugging a motor while it’s powered up, static, ect.