I have laid Quick Step Livyn LVT flooring in a lounge measuring approx 5m x 5m. It was laid on Quick Step brand underlay so it is floating type flooring. The floor was a new flowscreed that was left to dry for six months. In the middle of the floor there are now some quite large areas where the flooring has lifted a couple of mm. There is still a couple of mm clearance all around to the edges of the walls. A kitchen alongside is a similar area and is OK. Can anyone advise what has gone wrong ?