Here are two pair of pictures demonstrating the attenuation the switch in Windows caused:
For certain it is the Low Emissive glass in the new windows. Somewhere in the assembly will be a metallic film intended to triple or quadruple the energy reflectivity compared to plain glass.
A plain glass window is expected th attenuate less than 1 dB where Low-E glass ranges between 33 and 50 dB attenuation.
The phenomena is why WiFi and Cellular signals can often be blocked by mirrors. The metal film causes attenuation.
An unexpected consequence of upgrading Windows!