Since the Ray depends on an IR signal, there is a couple of things I’d be looking at. First, I’d double check that the ‘smart’ remote was set up to use IR, and not some other method. It’s been known in the past for QA folks to miss an update changing the remote from IR use to ‘smart’ use, through an update to the TV and remote.

The battery suggestion comes from a situation where the remote is too ‘weak’ in its IR signal, and it isn’t strong enough to be read by the Sonos.

I’d also be double checking that there isn’t something potentially blocking the IR sensor on the Ray, or even shining sunshine into it too much, which could obfuscate IR signals. 

Finally, I would probably go through the setup procedure again in the Sonos controller, just to ensure it’s reading the correct (and possibly new or changed?) codes.

Oh, one more thought. If none of that makes a difference, I’d call Sonos Support to discuss it.

When you speak directly to the Support staff, they have tools at their disposal that will allow them to give you advice specific to your network and Sonos system.

FWIW, I’ve seen cases with some TVs (Plasmas)  shining enough light to disturb the IR sensors, so you’ll want to be careful about what could be shining in to it. Could be a table / reading lamp that’s changed just enough to cause the type of difficulty you’re reporting. IR can be somewhat sensitive, since normal humans can’t ‘see’ the light signal.

Also, at what angle is the Ray in reference to your remote. Some remotes that are line-of-sight have a very narrow spread. If the receiving product is too high or too low as may be the case especially in a bedroom the line to attenuate the volume may require more extreme angle positioning of your arm/hand.

Some Samsung TV’s do not make the remote emit ir signals if you switch from bluetooth, but make the emit the ir signal. So maybe you need a line of sight between TV and Ray?

Thanks everybody for your suggestions. I have configured things correctly (as far as I can tell), and there is nothing blocking the signal, my TV is directly in front of my couch with nothing in between. There is also nothing I can tell that could be blocking the signal, and no sunshine (this happens at night) or glass or anything like that around. I’ve gone over the configuration multiple times and the issue happens again.

It has gone back to working a bit more often now, but it can be working for, say, half an hour, and then all of a sudden it stops. Sometimes if I press the physical buttons on my Ray to change the volume and try the remote again, it starts working correctly, at least for a while. But not always.

I don’t have a good idea of the conditions which make it fail or not, it seems quite random. Maybe when I’m standing and pointing the remote down to the speaker it works more often than if I’m in the couch a bit further away and facing it more or less directly (horizontally). My Ray is right below my TV, in case it makes any difference.

I guess my best bet is to call support...

Meant to say “but make the TV emit the ir signal”.

OK… 

You need to run a diagnostic within 10 minutes of the failure. Make note of the Reference ID. Do not post the ID in this forum. Then as ​@Airgetlam suggested call Sonos Tech support to discuss the data.

IMO, I think it’s more tied to the remote than an issue with the Ray IR receiver. However, I could be wrong. Good luck to get your issue resolved!

EDIT:

If it’s determined that it’s your remote that’s at fault you might consider an IR Repeater as shown in this link. The premise is that your remote has a bigger target to hit (the receiver node) and that signal is forwarded/sent to the IR Transmitter which is positioned in-front of or near the Rays IR receptor.