@Aki checked your photos and with factory. I now understand the reason and it shouldn't happen on later batches. Reason is that I wasn't satisfied with the first paint job for the pink, so I asked for a second layer to be applied. The parts were then painted assembled including the screws, as a result they are stuck tighter. Normally one shouldn't need that much force to unscrew. This time round pink can have this issue, sorry 'bout that