Please repost/reply here your original issue.  I can’t find it. Also what brand/type of HDMI did you use?

I am using WireLogic brand from Costco. 4K compatible high speed cables. About $30 up in Canada.

I appear to have missed the original problem.  Were you having audio lag problems, as many including myself have had using the HDMI ARC connection?  I myself went through that problem (see my posts), and ultimately ran a separate Optical from each source through a switch to the Beam.

Mine would simply not recognize the HDMI ARCport on my Samsung TV.

wow.  that is crazy.  I had just bought a 2019 Samsung 75” Q80.  The port worked but had extreme audio lag - like a badly dubbed movie.

I used the HDMI cable supplied with the Beam and it works fine with my Q80T’s HDMI ARC interface.  You probably just got a bad cable; it happens sometimes, but it’s one of last things you would think of when troubleshooting.

@Bargie @Mike Thurst   After many months on the Optical I tried the HDMI ARC port again.  Lo and behold, it’s not giving the audio delay.  I keep track of the firmware updates on the TV and maybe the the S2 update to Beam did something - no idea.  But here’s one odd thing, the audio was now slightly faster than the video.  Almost imperceptible.  So using the TV Sound/Expert settings, I added a slight delay.  
Now the HDMI port is functional, I found some movie content that had Dolby Digital+ , but when I change the audio to that I got no sound.  Any ideas?  I may go get a new cable, but the one from Sonos is at least functional to remove the original audio lag problem.  

@Airgetlam You have considerable knowledge on these topics, what do you think?

Thanks

update: I just remembered the Beam doesn’t support DD+ .   My ignorance.   That’s what happens when I got so excited that the HDMI ARC port now is working.   Now got to decide if I want to upgrade to the Sonos Arc.   I know I won’t probably get Atmos,  but oddly, my TV settings have a selection for that.  But I wonder if the sound stage is better than the Beam   

Atmos also works via DD+.

You’ve answered all your own questions. The Beam doesn’t handle Dolby Digital Plus, and the lowest capability required for Atmos is Dolby Digital  Plus. The Beam, the PLAYBASE and the PLAYBAR will never be able to decode Dolby Digital Plus, and never be able to handle Atmos content, they’re restricted to Dolby Digital 5.1.