Welcome to the forum. I would say no, not normal.
It sounds as if there is a binding or misalignment in the lowering mechanism.
If you can locate the source of the 'pop' without pinching your fingers, see if it is from a loose or dry joint.
Having a helper work the vent button while you watch from the outside may give you a better view of the pop. Stand on a footstool to get a good look from above.