Hi @rickj63.

Welcome, thank you for reaching out to Sonos Community, We appreciate your time and effort in posting your concern here in our community.

Have you already check the manual for your TV it should have to do with the TV settings.

Check also if the TV is up to date.

Let us know if it works. If you need help with any other information, please be sure to let us know.

Do you have TV Autoplay enabled in the Beam settings? If so, disable it.

Edit. On re-reading your post that is unlikely to be the issue. It is unlikely to be anything to do with Sonos.

So the tv is forgetting that you selected “use external speakers”? Sounds like a question for the tv maker. From your post it seems to be a problem with the “new tv” that didn’t happen on the old one. 

Sorry I can’t offer any solution, but something similar has started to happen on my LG Nano866 TV. Randomly the TV reverts to the internal speaker settings when switched back on. But it does show internal speakers as the selected output. Easy enough to toggle the setting back to HDMI ARC out, but a bit frustrating. I am assuming there must have been some TV software update as as far as I am aware the Sonos device and/or App software hasn’t been updated recently.  

That would be super annoying. If Philips don’t have a fix for that, get another TV.

TV is up to date . Iam not alone in this senerio .

Who knows weather its a TV issue or sonos as no doubt both will blame each other .

As its used in  2nd lounge and the beam is not atmos compatible I used the optical/HDMI lead and it now works fine . All the HDMI on the TV are all arc and no obvious check on settings menu ,Happy to stick with optical as it frees up a HDMI connection but others might not be . Previous to this has a Yamaha yas 306 ,and Sony atmos which both worked fine with the TV.