3/4 royal mahogany

The Royal Mahogany web site shows an underlayment product called SilentBlue. Could this be what you see under the floor? It is listed as [b]waterproof. The NWFA recommends a semi permeable vapor retarder between the sub-floor and finished floor. Can you ask the installer why they used this product? It could be preventing moisture dissipation between it and the sub floor and it and the finished floor?

No it's not that type. It is like a glossy photo paper light blue in color on one side and white on the other. Also, when pulling shoe moulding i do not see it overlapping the woodfloors. I see bare plyboard subfloor. Is it possible the installer did not place the underlayment all the way to the baseboards? Could this be allowing moisture to the floor? Again, most areas do not show any expansion gap most are flush to the baseboard. could this be causing the problem?

You mentioned that you have been in contact with the company that did the installation. Can you ask them what the light blue/white product is?