Is it all phasing or is it something more?

Previous responses have hinted at this but didn't quite get there. Stream the movie again and wire your speakers out of phase and see what happens. It sounds like the stereo soundtrack may be out of phase and it is easy to test this.

There was an article in the NY Times recently discussing why over 60% of Netflix viewers use closed caption sub titles- it's due to the combination of too many loud sound effects over powering the dialog, a trend for actors to be whispering / speaking at low levels for "dramatic effect" and lastly that many movies are of course mixed for surround sound and increasingly for Atmos - so the downmix for TV audio is compromised. I don't think playing with a phase switch will do much for you.

I have several CDs with one or two tracks recorded out of phase. This is a technical mistake, and easily corrected changing the phase of one channel. However, I have also heard some New Age music and some instruments were recorded out of phase to give an ambient effect. It also prevents you from localizing the instrument.

You can take a 30 sec long segment of the audio and change the phase of one channel to see if it improves the sound.

Speakers are definitely in phase as this is the only content that I notice it on plus I hear the same issue on my girlfriend’s system. Still wondering if it reproduces on non-streamed DVD or Blu-ray media. 

I was on my phone when I relied earlier, but it is worth checking all of your speakers to make sure they are in the correct relative polarity.

You can use a 1V to 9V battery to test that the woofers move in the same direction. Attach + to red and - to - and see which way the woofer’s move. Usually they all move towards the listener. Any that do not need to be inverted. Once that is done, make sure that the wiring at the amps is what you expect.

If all your speakers go the right way, then they are all red to red. That is, red on the speaker and red on the amp. Any that go the wrong way you swap, black to red.

For the battery testing, you'll need to connect both ends of the battery to the speaker.  + to red, and - to black.  A short length of zip wire will also be needed.

Most cant detect absolute phase ( polarity )issues at all, but do hear relative phase.  that is, if a channel is inverted relative to another.