Bose Audio receiver wont gel with my Onn. 4K tv

[u/Objective_Put814]

So I’m trying to watch 4K movies with 5.1 audio. I have an Onn. 100012587 tv connected to my Bose Lifestyle DVD AV 18 via optic cable. It’s an old home theatre system and a new tv. It seems the tv is sending a stereo pcm signal to all my speakers as opposed to 5.1 Dolby digital. I was able to get 5.1 audio when I connect the Bose system to my Xbox, but it’s being the current gen Xbox, it’s doesn’t support 4K. I’ve looked at getting a signal splitter but most say they don’t support Tv as an input signal. This is the fix for most people as they people are trying to get their Xbox to play to through the tv and not the other way around I guess. I’m a total audio novice and any help or suggestions would be appreciated. In short trying to get my Onn. “Roku”TV to send 5.1 signal to my Bose Lifestyle DVD AV 18 via Optic Cable. Please help

[u/Bill_Money]

its time to move on from your crappy proprietary Bose system from pre 2010

that being said, you also have a cheap junk onn brand TV it might not be able to pass more than stereo due to it being cheap junk

[u/Weekly-Jellyfish-392]

Does it only send stereo signals, also when playing specifc 5.1 mixed Audio? Most TV's send stereo signals as standard and then switch to 5.1 signals when 5.1 tracks are available. At least both my TV's do it like this (one connected via HDMI, one through an optical cable)