Same question here, I've a Harmony hub inside my TV stand, IR repeter on. I see the led on the ARC but commands are not received by the TV.

The IR sensor IS although on the left side of the TV (,Panasonic GZ1000)

I’m having the exact same issue as OP. Arc is setup, IR repeater is enabled in the S2 app, but the only TV controls that process are volume up/down. The remainder are not passed through by the Arc to the IR input on the TV (which the Arc blocks). 

I was hoping my input button on my Panasonic remote would pass through somehow. Is it supposed to go via ARC?

I'm having the same issue. Had to boost up the TV to get the TV remote to work

Does the Arc have an IR repeater?

I’m also wondering where on the Arc the IR Repeater is actually located. I have 2 Arc’s - 1 connected to a GZ1000 and 1 connected to a LGC9 - and like you guys I have to aim up over the Arc for anything other than volume to work. And yes it’s toggled on in the app for both of them.

Looks like we're all having this issue. My IR repeater doesn't appear to be working and my Sony Bravia IR receiver is in the middle. 

The volume up and down works but that's passed through the ARC port.  (I really think they should have given this speaker a different name)

Same issue with me. Love the ARC, but IR repeater doesn't work. Also wish they supported the sound setup the same way they do with IPhone. Will probably borrow someone's at some point to calibrate to my room. Was also hoping it could stream Atmos audio from Tidal without going through TV but no luck. Will be upgrading my tv, so no big deal, but something I didn't know about.

Hi everyone, there are IR repeaters on both sides of the area where the cables are plugged in on the middle (called the cable cove), designed to broadcast the signal out to both sides of the bar from the back. As long as the IR receiver of the TV isn’t hanging over the back of the bar, it should be able to see the signals.

If you’re having trouble, maybe you need to just pull the Arc forward a bit. But if that’s still not working, you may want to give our support team a call to investigate further.

Okay, so I was able to get mine to work. The IR repeaters are on both sides like what Ryan S. said. I had to pull the sounbar forward another inch or so and it is working now. The IR repeaters fire upwards instead of backwards, so the light can't hit the TV if it is too close.

Scratch that. IR repeaters don't  work. You can check by looking through your cell phone camera as you press buttons on the remote. Cameras pick up IR light and the Src is not transmitting anything through the repeaters on the back. Hopefully an issue that can be fixed by a software update

@Ryan S  I contacted support via chat earlier today., Before I even get into that I have a question. What are the purpose of the IR Repeaters. I know it sounds like a ridiculously silly question but I promise I am asking for a reason.

Do they only repeat the IR commands for volume or pretty much all IR commands.  I figure they should just send what they receive.

This is what I've been leaning to as well.  I will wait on @Ryan S first before I commit to that statement.

Some smartphone cameras have IR filters, test the camera first with remote. eg my iPhone main (rear) camera doesn’t see IR but front face camera does see IR from remote.

Using the suggestions and info in this thread I think I have located the repeaters.

As already stated they are not visible to the naked eye but can be seen by a smart phone camera.  

Surprisingly they stay illuminated all the time it appears.

I do not know if that's normal. You would think they would just send a burst of light like a typical remote control.

I also wonder with them being so recessed like that could that interfere with communication to the TV. 

The IR repeater will broadcast any IR commend the receiver sees, it doesn’t apply just to volume commands. And yes, the IR lights will be on all the time, they flash when sending commands.

Thank for clearing that up @Ryan S .  As I mentioned earlier in this thread I contacted Sonos support about this issue. After a rather drawn out chat session the support rep tried to convince me this was not the case.  As nicely as I could informed that he was incorrect.  Really kind of sore about that. I'll send you message directly on that.  I saved the transcript of the chat too. 

I'm going to test to see if the repeaters are flashing when using my remote after work today.

Thanks again Ryan. 

I tried mine earlier and they definitely aren't flashing like they should when they get a signal from the remote.

maybe an issue with the S2 app?

So has anyone got this working yet after moving the Arc forward more, as suggested by @Ryan S?

I moved my Arc so that it is around 20cm in front of my GZ1000 (it was already 15cm in front) and still nothing is being recognised, other than volume of course.

No one has a fix yet. I called customer service and they are aware of the issue. I did notice by using my camera that the IR repeaters are working if the remote is used at a very close distance, about a foot from the soundbar. However, when I am sitting at a normal distance away, like my couch, the IR repeaters do not flash. I've tried different batteries in the remote and have the same issue. Maybe some sort of sensitivity issue with how the ARC is processing the IR signal from the remote and passing through the repeaters.

I've communicated with customer support and they basically don't have a fix. Ive been told that maybe it is something with Samsung and I should contact them. I don't think it is an issue with Samsung, as the IR repeater should work regardless of the TV. I would keep this in mind if you decide on the Arc, the IR repeater may or may not work as it should with your TV. This won't be an issue if you mount your TV above the soundbar or obviously if you are using HDMI ARC instead of the optical connection. I don't feel it is worth sending the Arc back as I plan on getting another TV and mounting anyway, but you may want to keep this in mind if you don't have this option. 

Typical. Blaming the other party.

I had a Panasonic HTB900 prior to the Arc. The Pana IR Repeater passed all remote presses just fine. The Arc in the exact same spot, does not. The Arc, pulled forward to give more space for the signal, does not. Really is annoying having to point up over the Arc to change channels etc.

*Typical. Blaming the other party.*

Exactly. When enough people notice it isn't working properly, they will hopefully decide it is worth actually fixing.

I'm working through with Sonos support. Having same issue. Try moving Arc further forward. Playbar worked fine