Hi

You’ve got your connections incorrect…follow the steps below in the indicated order:

1. Disconnect all devices including the Beam2
2. Factory reset your Beam 2 and set up as new. Click here for instructions for factory reset.
3. Connect the Beam2 to HDMI 2 which is the eARC port and engage CEC (Simplink) in the LG HDMI settings menu
4. Connect the Panasonic and Fire Stick to other available HDMI ports

Click here for a description of your TV’s HDMI ports found under Specs > Connectivity in the displayed page.

Cheers!

@Big-Gee 

Did you get your connections corrected?

This is rather puzzling as all the OP is doing is swapping the source device on a system on which the connections were already working. (Unless I have completely misunderstood.)

What audio output format is your BRP set to use?

I am afraid I have no idea what you mean by the Home screen and the Sonos screen.

@John B 

The OP had his devices connected incorrectly as per the link in my post. The Beam2 should be connected to HDMI 2 which is the eARC port. Sometime things work even though connected incorrectly, until they don’t. Unfortunately, the OP has not responded in over 24 hours so we may never know the outcome.

Very sorry for any confusion, but I can confirm that the Sonos beam is connected to the HDMI interface marked eARC/ARC, and the DVD Player is physically connected to the other HDMI (marked HDMI 1), is not switched on yet the TV (Home Dashboard line on page marked by symbol of a house) indicates BD_PLAYER is connected to HDMI 2. When I select this, the screen displays close up photos of sonos products and logos, and overlays HDMI 2 BD PLAYER. When the DVD Player is powered up and play is selected, the counter begins but the picture/sound doesn't change. 

When the DVD connection is replaced with the firestick, the home dashboard shows Fire TV Stick connected to HDMI 1 and, when selected, this plays normally. 

When any of these play a recent 4k/UHD movie my sonos app indicates the sound is playing PC STEREO. I would have expected it to indicate DTS at least, or ideally Dolby Atmos. But maybe this is another question. 

So the TV thinks the BRP is connected to HDMI2 when it’s really on HDMI1?  This sounds like a CEC (Simplink) issue of some sort.

You haven’t got any CEC adapters anywhere?

Can you turn CEC off, even if it means playing through the TV’s own speakers to start with?  It sounds ilke you can’t even get the video working, which makes it unlikely to be a Sonos issue.

Can you turn off CEC for individual devices on your TV?

Hi

Please disconnect all device as indicated in step 1

Then reset your TV to factory settings to erase any previous connection data.

Follow steps 2 thru 4

Let us know the outcome

We can discuss your sound issue after we resolve your connections issue

FYI, this not a Sonos issue. There’s something going on with your TV. Therefore my suggestion to factory reset the TV.

Cheers!

Thanks for the suggestion, I'll do this, at a convenient point in the next 24hrs and let you know the outcome 

Sorry for the delay. I have initialised the TV per initial installation. During this time the dvd player was connected to HDMI IN 1, but not powered on. The Sonos was connected to the HDMI interface marked ARC /eARC and was powered on..

Attached is a photo of of the screen if I try to play a dvd... 

The Sonos, is working as a speaker for the TV or from my android device (phone) 

Still seems like something with your TV. Removing the devices from the TV not just powering them down was a critical step. Please reset your TV with all devices removed. Reset the Beam2 as indicated. Then follow the other steps. If that doesn’t work contact Sony and/or submit a diagnostic to Sonos Tech support and post the reference # in your next post.