Oh that's totally fine, I do it too and I don't think many people can reach the higher strings like that. That's not a problem because you still get a good angle when fretting those strings, but you want the same kind of angle when fretting the lower strings - thumb around neck. To explain it better, I always hold the guitar so the bottom of the neck is resting on the finger joints just above the palm (the back of the knuckles) and twist my wrist a little when doing a bend/vibrato on the lower strings so the neck sits on the joint of my index.

Try practicing this and you should progressively ear the noise disappear with your pull-offs