I have a TCL 4 series. Just bought a Bose Solo Soundbar Series 2.
When plugging in the optical cable it came with, I am only getting sound through the TV.
The only options I see when going to
Settings > Audio: I see Sound Mode, Audio Delay, Audio Mode Only, and Advanced Settings
Settings > Audio > Advanced Settings: I see Balance, Audio Volume Control, Digital Audio Out, and Digital Audio Out Delay.
Under Digital Audio Out: Options I see are Pass Through, PCM, Auto, and Off.
None of these options work, sound still comes out of my TV no matter the option.
Return the soundbar if you can.
Putting any kind of money on a Optical audio solution is absolutely craaaazy in 2022-23.
You want one with HDMI-IN. Simple as that.