At a molecular level, what is actually happening inside a shear-thickening non-Newtonian fluid (like oobleck) when it is subjected to sudden force?

We've all seen the classic science experiment of mixing cornstarch and water to create oobleck. If you press it slowly, your hand sinks in as if it were a normal liquid. But if you punch it, it acts like a solid brick.

​I know the macroscopic explanation is "shear-thickening," but I am trying to understand the exact physical mechanics occurring at the microscopic/molecular level.

​When the sudden force is applied, what is happening to the cornstarch particles and the water molecules?

Are the water molecules being physically squeezed out from between the starch particles, causing massive friction?

Why doesn't this locking effect happen when you punch a similar mixture, like wet sand or flour and water?

What specific molecular geometry makes a substance shear-thickening?