Unsure about my new lock & fold floor

pr57001

I recently had a lock & fold bamboo flooring installed (purchased from Lowe's). Previously, there was 3/4" hardwood installed over plywood over concrete slab. Water leak warped previous floor, any wet plywood was replaced. Underlayment on top of plywood and then lock & fold applied.

It looks very nice, but when you walk on it it feels like it has too much "give" to it. So much so that my wife indicates she can see it depress as I walk through the room.

Given this is a far cry from true hardwood before, can anyone explain if this is at all normal? Was installing it on top of plywood on top of slab an incorrect method?

Thanks for your help.