If you have tried another 1.4+ HDMI cable with heac support and that is working okay then contact Sonos customer support to see about arranging a cable replacement . Here is their link:

https://support.sonos.com/s/contact

What TV? Are you certain is HDMI 4 port? As Ken suggested try another cable. Any version will do as they are backwards compatible. Is it perhaps an eARC where you need to enable simplink? For example in my LG c1 I need to enable simplink (HDMI-CEC) in sound settings otherwise just plugging it in doesn't work.