Is the Sonos connected to the port labeled ARC? What kind of signal is the Blu-ray player sending to the TV?

Yes it is via HDMI 3/ARC and Blu Ray is also connected to Sony TV with HDMI 1

Could you answer the second question, please? Is the controller’s ’now playing’ screen showing anything?

Have you rebooted both the TV and Beam? Have you submitted a system diagnostic within 10 minutes of experiencing this problem, and called Sonos Support to discuss it?

There may be information included in the diagnostic that will help Sonos pinpoint the issue and help you find a solution.

When you speak directly to the phone folks, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

Set your TV to these settings:

Speakers: Audio System

Audio System Prioritization: On

eARC: Auto

Digital Audio Out: Auto 1

Dolby Digital Plus Output: Dolby Digital Plus

Pass Through Mode: Auto

Set your Blu-ray player to this setting:

Digital Audio Out: Auto

thanks for all the helpful tips. I will try all of these and see if that solves the problem.