Laminate crackling sound after fit

I had new laminate fitted Dec and within 1 week started making cracking noises. Joiner tried to lift and refit but unfortunately noise still there. I had laminate previously but never had this problem so don’t know cause. Joiner didn’t not know what has caused this either. Flooring company haven’t had any concerns with flooring. Apprehensive to get lifted and layed again for same prob to arise. Any advice would be greatly appreciated.