Dolby Digital Audio Not Playing on Netflix App - Sony KD-55XD8005, Yamaha HTR-3065

Hello.
I have a problem playing Dolby Digital audio from the Netflix application on a Sony KD-55XD8005 TV. When you select 5.1 sound, the speakers are silent and the receiver displays Decoder off. After selecting stereo sound everything works ok.
However, the sound broadcast by TV stations is sent in a steady manner in Dolby Digital
TV connected by HDMI cable (ARC) with Yamaha HTR-3065 home cinema.
Has anyone encountered a similar problem and solved it?
Regards
Andrew

check the TV settings

Ie?
I have set the TV so that the sound is fed outside. Besides, as I wrote, the sound from TV stations is sent in Dolby Digital. The problem only occurs with applications. I just checked YouTube-Dolby sound missing.

Read, maybe it will brighten something. https://community.sony.pl/t5/telewizory/netflix-5-1-gdzie-sie-podzialo-dd/td-p/2298950