Will the sound stay 5.1 after traveling through HDMI and optical cable?

Question

HDMI

Hello. Now I'm choosing a TV and I'm faced with a choice: a TV set with a built-in smart tv or a regular TV with an android tv set-top box connected via HDMI. I tend to the second option, so I want to clarify some of the nuances before buying, so that there are no surprises.
Here is one of those nuances. I will connect the TV with an optical cable to the home theater. If I turn on video with 5.1 sound on the set-top box, will it be compressed to stereo on the way out? Does the answer depend on the specific prefix? If it does, is it possible to find out about it before buying? Usually reviews do not touch on such aspects.
For clarity, here is the connection diagram again:
Android TV <=HDMI=> TV <=Optical=> DK

Answer 1

You need to look at the specification of outputs on Android TV and on TV - in what form they support Dolby Digital.