Everytime I transform WFC Siege Starscream from jet to bot, the pieces that should split from the nose jet to the shoulder vents lock incredibly stiff, and I've needed to use a knife to split them which is damaging the plastic. It looks like there's something that could be sanded off to make this locking peg less strong? I can see the plastic bending when I'm forcing it apart. I looked at video reviews and they just mention "oh it's a stiff joint" and proceed to ultimately unlock it with their hands but my copy is impossible. Anyone else ran into this problem?