Yes the Ultra accepts IR commands as well. Only Roku sticks like the 3810 Stick+ doesn't accept IR commands and so won't work with your harmony.
Thanks TivoB! I just read about the 4K+ uses smartphone to listen to TV, so I don't have to upgrade to the Ultra to have the aux jack in the remote. I might be able to re-pair the one I have now to work with 4K+ also. So, I pre-ordered the Express 4K+. I can't wait! we will finally be down to one remote and an occasional roku remote or phone to listen using headphones.
The Roku does have the latest update. When I 'checked now', it had no updates available.
Yes, the C7 has 6.00.05 installed.
Yes, I have SIMPLINK on the C7 enabled and 1 touch play enabled on Roku. Very good questions -- I had to verify them all....but it appears all of these are in order.
I'm having the exact problem using my Express 4K+ remote with both my 2020 Samsung TV and my brother's 2021 LG TV. Software for the Roku Remote and both TV is up to date. Remote's voice control and channel control work, but turning on/off and volume control don't work. If somebody could tell me the name and model of a couple or more ALL the TVs Express 4K+ features will work with, I'd be very appreciative. Geesh, wouldn't you think Roku would mention the fact that all the remote's features may not work with some TVs....and then give us a list of TVs that will be able to use ALL the remote's features? Sure would save us customers and Roku's customer service reps a lot of time and trouble, not to mention aggravation. This is no way to win friends and influence people.
You re-setup your remote? Settings/Remotes & devices/Remotes/<remote name> (In use)/Set up remote for TV control
I resetup everything, but finally just gave up. Volume for my LG+Soundbar never worked. Sorry to report the bad news.
Same Roku, same late 2017 LG 4K TV, same problem. It tried 7 or 8 times to hear music (i did), then it said Unable... LG remote controls TV power and Vizio soundbar no problem. Roku remote - no way... I'm in HDMI port 1 on LG.
*The iPhone Roku remote app also no go re: volume & power...
Update: Try this. IR worked for me on my LG 4K 2017 49"
https://www.youtube.com/watch?v=CRFMcyDNGqY
I detest my LG TV. It has been more difficult since day one and constantly logged me out of apps when updating, never added HBO channel for years (may still not be there) though I was able to finally find the AppleTV app and add it to the LG channel line up, but I never watch anything from there. The LG interface is just a right headache, which is not what you want when curling up in bed to watch tv. Beautiful picture, terrible interface.
My older Samsung has run flawlessly with the same Roku system as on the LG.
Which is just to say, you and/or Roku are likely not the problem. I think that is the same Roku system I have (I've had a couple) but I now completely bypass the LG buttons. I pointed the LG channel mgr to my hdmi1 port where my Roku is plugged in, left it there, and only watch thru my Roku now. There is less cursing that way. The only issue I have occasionally is the Roku remote power/volume interface (to LG) sometimes drops off my Roku remote and I have to grab the LG remote to mute, etc. I can't compare that to my Samsung because it has a soundbar and the roku remote won't power up/control those at all (seems that shouldn't be insurmountable, Roku? A rhetorical question.
As I mentioned in a previous post, I read somewhere in my Roku set up information that you cannot sync the tv power/volume control to your Roku remote if the tv is using a soundbar. It's as if there is one pathway/channel and the soundbar took it so your roku remote can't have it. There must be a technical reason. I have to use my soundbar remote to control volume, etc, on Samsung tv though I can power up/down with my Roku remote there. LG has to be powered up with LG remote but no soundbar so Roku remote sync'd up easily. There must be idiosyncracies with various tv brands.