Hi @AZ_Kohler,
Unfortunately this is a fairly common problem that has no one-size-fits-all solution. To make it clear, your Sonos player isn’t changing its own volume, nor is it really in control of what volume the content it receives is.
The problem here lies between the different content, and different sources. Each type of content, whether that be a movie, TV show, live stream or video will be mixed in a slightly different way - this even goes for content from the same service (i.e. not all Netflix movies will be the same volume).
Take a look at your TV’s audio settings and see if it has anything relating to audio normalization, and if it does, try toggling it on to see if it makes any difference.
If you’re primarily watching things at night and find that you’re experiencing a lot of loud peaks (like explosions or shouting), try turning on Night Mode from the Sonos app. You’ll find this on the Now playing screen and the icon looks like a crescent moon.