Live in condo.Whisper mat required for sound proofing under hardwood floor. After a few days we hear snap crackle and pop sounds. Not always in same place. Then floor began to buckle in certain areas. Flooring installed by master floor installer. He used glue and products recommended by manufacturer. He feels the noise is from whisper may which he has never used. Can you help?
Floor person here now removing boards that were raised. Seemed to been too tightly laid. Noise he can't remove.

I take it it was fastened over top some wood composite substrate? Could be badly weathered OSB or if they went over particle board, PB bad news.