Lamian (Hand Pulled Noodles) Technique Question
I have not made these noodles, but what you describe is normal. What are you seeing is gluten production happening. And you don't want to prevent it, it's why you put the whole alkali stuff in there in the first place! 

Gluten is a very elastic stuff. Dough behaves (and tastes) very differently before it's formed. Pulled noodles need stronger gluten than other doughs like bread, that's why they use lye (typically) or a baking soda substitute (much weaker, but some cooks are uncomfortable around lye). Simple flour + water or even flour+acid doesn't create strong enough gluten for that. Rested gluten does indeed allow for easier pulling, but while you work it, it behaves exactly as you described it: pulling back, and then even seizing. 

From my experience with pulling other doughs (e.g. pizza shaping by hand), I'd say that 1) if there is a resting step in your recipe before you start the pulling, take it seriously, and 2) a lot of it is simple experience. You continue doing it until you learn the motor skill properly. The first few dozens of tries will be battles resulting in irregularly shaped dough, there is nothing unusual in that.