PS4 Pro to 4K TV via HDMI ARC , but no 5.1 Audio receiving by Surround System

[Rukshan]

I have connected PS4 to a 4K TV via HDMI/STB port, then, TV is connected to a 5.1 Home Theatre system via HDMI/ARC port.
If I plug in a USB drive to TV and I watch a movie with 6 channel (5.1) sounds, Home Theatre System receives 5.1 audio fine via HDMI/ARC.
But it doesn't get 5.1 audio from PS4 games. Isn't this possible with ARC? is this because HDMI bandwidth is not enough when outputting a 4K video signal via HDMI cable ?

If I'm going to use a separate optical cable should I directly connect it from PS4 to Home Theatre System (this seems obvious option) ,
OR if I connect TV to Home Theatre with an optical cable, will I still get 5.1 audio from PS4 games? Because probably TV is already receiving 5.1 audio from PS4, but HDMI/ARC won't output this to home theatre system. (both TV and Home Theatre System supports DTS and Dolby)

And I also , would a normal optical (Toslink) cable support Dolby Digital or DTS ? (I read somewhere that you can't use normal optical cable to transfer Dolby Atmos or any other new HD audio codecs, so this shouldn't affect normal DTS or Dolby Digital isn't it? )

 

[Rukshan]

I got this working by changing audio output settings in TV.

 

[karimterveer]

I got this working by changing audio output settings in TV.

Hi, I have the exact same problem! I have the exact same setup as you do as well. Which settings did you use in the tv output? And which in de ps4 pro audio output settings? With me I set is both to PCM, but it doesn't work.

Hope you can help me out.