It was changed into Google TV on phones only, now it's being killed on Android TV's. Extra layer to the confusion, depending on what platform you are using changes what the app is named...
What texting app are you using? I have sadly had to stop using Textra all together due to similar issues with not getting messages across multiple phones, but everything works fine on Google messages.
Steamos 3 (the steam deck) is based on arch. They moved off of gentoo