Ah, flex. That is what I was referring to in my closing comments.
This can be aggravated by the following:
not flat subfloor
not clean subfloor
not smooth subfloor
Poorly milled/formed board edges
As to the last item - This could be things like not having the boards tight or interlocked correctly.
Laminate and engineered floors don't typically have issues with warping so othat is not a likely problem. If you do have warped boards TAKE THEM BACK. The should be perfect.
If I were a betting man - I would guess you problem is a wrinkle in the underlayment or something else under the floor (an old nail/screw in subfloor not flush, glob of drywall compound, stone from your shoe, even coarse sawdust)
or, it may be its normal characteristic.