You are not alone. See the topic with the title "No sound between TV and ARC since app update." (May 26, 2024)

Same here! And the optical adapter that followed Beam 2 is not supported anymore by Sonos… Like wtf. I’ve been without sound for over a month and customer service simply does not know anything. 

There is no reason why the app update would stop an HDMI-ARC signal from the TV to a Sonos device.  I’ve seen Beams/Arcs go years without even connecting to an app and the HDMI connection works fine.  Something else is at work here.  The first thing to try is to check the settings for the soundbar room to make sure TV Autoplay is turned on.  Next, check the TV to make sure CEC is turned on.  CEC is the generic name, here’s a list of the brand names:

• Anynet+ (Samsung)
• Aquos Link (Sharp)
• BRAVIA Link and BRAVIA Sync (Sony)
• HDMI-CEC (Hitachi)
• CE-Link and Regza Link (Toshiba)
• SimpLink (LG)
• HDAVI Control
• EZ-Sync
• VIERA Link (Panasonic)
• EasyLink (Philips),
• Realink for HDMI (Mitsubishi).

If CEC is working, try forcing an HDMI handshake by pulling power on both the TV and the Sonos device, and waiting 10 minutes.  Plug both back in and allow to come up.  

Have to turn off the tv and Sonos every time I want audio on the TV since the last Sonos update. Wish they would stop breaking everything with each update. Anyone found a solution. Arc soundbar connected to Samsung frame tv. Sonos used to be excellent but has really gone downhill.