I’m not familiar with your TV. Power down both the TV and BEAM before making the HDMI connection. Typically, as the the HDMI connection is established, TV and BEAM will discover each other and complete the necessary details.

So you say:  power down the tv and beam, make the HDMI connection and then power on both?

Remember, the Sonos is getting volume commands from the TV set, via CEC, and not directly from the remote itself. So ARC or eARC must be turned on on the TV set. 
 

Not sure what the ‘internet’ was talking about regarding Philips. The remote needs to be connected to the TV set. Same as the Beam. The only time things can change is if you’re using a Sonos Ray, or a PLAYBAR/PLAYBASE, which don’t have an ARC (CEC) connection. Those devices connect via optical, which does not carry any volume information, so the Magic Remote needs to be set up differently. 

I recommend powering up before connecting the HDMI.

The selection of Philips as the manufacturer is an old fix - the LG ‘device connector’ now allows a user to search and add ‘Sonos’ as the Soundbar manufacturer (see attached screenshot), but note this is for universal remote control of the Sonos Playbar when it is attached to the TV’s S/PDIF optical port only. I would still set it up however, even if using an HDMI-ARC/eARC connection to the TV, as it provides some TV on screen controls for the soundbar. 

When using the ARC/eARC (HDMI-2) link to the soundbar - both Simplink and ideally Auto-Power-Sync needs to be enabled in the TV settings. The Magic Remote should then work with the TV/Soundbar.

Problem is solved

Thanks alle.