Solid Hardwood, Engineered and Laminate Flooring - Laminate question

I just installed Dupont laminate flooring from HD that looks like tile. I checked my floor level and everything seemed within tolerance but the one corner near a stairwell door seems to flex a good bit when you walk on it and is slightly out of level(less than 1/8 of an inch). Should I be concerned about this? It drives me crazy everytime I walk on it. If it's a problem is there anything I can slide under it to level it out? Thanks

I'm not too sure about whether it will cause you problems other than annoying you but if you need to shim it I've read a lot about people using roofing shingles I believe. I'm sure an expert will be by & able to elaborate more on this or whether it's even something to worry about, though I've found in the past if it bothers me, then it's worth fixing. Just my 2 cents.

If you can get it under there and it provides support, use it!!

Cardboard, roofing felt, newspaper, old Christmas cards.. Hehehe!! LOL

Thanks for the responses guys. I thought about trying cardboard but wasn't sure that would work. Fortunately I haven't installed the transition pieces yet so I'll be able to slide something under that section easily. Thanks!