Sonos arc ultra - losing sound

Hello, I replaced an old playbar that never failed with a Sonos Arc Ultra.

My new current settings:

Sonos arc ultra 

TV sony xf9005

Apple TV 4K first generation

Connection Sonos arc to tv - hdmi ARC, Apple TV to Sony TV - hdmi cec

Unfortunately, this is the beginning of my problems.

As I change the channel there are no sound. Then I change the channel again and the sound comes back. When I pause what I’m watching  it loses sounds when I resume. Sometimes help me pause and play again and sometimes i must restart movie. 

I have reset the system, unplugged, changing hdmi cable, update firmware etc... (all recommended things by sonos chatbot)

I contacted sonos support with chat and they told me that the problem is known and caused by the last update and that it should be fixed but they don't know when.

I am very disappointed, I wanted to enjoy the new equipment and not wait for an update that will come who knows when.