Road noise like loud humming (not tires just checked) does not vary with engine rpm

What is your question?

Just noticed noise a couple of weeks ago and thought it was tire related but new tires did not change anything. Noise gets louder as speed goes up. No noises noticed when turning either direction. Just had all new brake rotors and pads installed before noise started. Noise did not start immediately after new brakes installed. Also had right front CV joint and half shaft replaced.

What makes this problem better or worse?

Noise seemed to start when it got cold.

How long has your 2015 Subaru Forester had this problem?

A couple of weeks