Powerchain before closing gaps

I am currently in my 7th month of braces and during my 6th appointment the orthodontist put powerchains from my canine to my back molar in order to close the extraction gaps.

Suddenly in my last appointment she decided to take it all off and put powerchain on ALL of my teeth. Wouldn't the powerchain have an equal force on both sides and as a result the canines won't budge? I also feel like one my canine moved back to its orignal place.

This left me confused because I thought we were on course to close the gaps. Is this normal or have you heard of such cases?