Bought the 3800X as soon as it came out. Remote worked for my Insignia TV's power and volume from day one. May 2021 the software update caused me to lose remote power and volume abilities for my TV. After a few days of repeated attempts at re-pairing I got it to work. I posted about this here. Five days ago I had to perform a factory reset on the Roku and since then have lost the remote power and volume for the same TV. Repeated attempts to re-pair have been unsuccessful.
Seems like there continue to be a lot of users impacted by this. I contacted support directly and the best I could get was someone who was clearly just walking me through the remote trouble shooting featured on the website. Have been considering upgrading to the Ultra, but can't justify buying products from a company who can't patch a software problem they caused 3 months ago, or issue a formal statement about their current inability to do so.
I'm having the exact same problem only with our bedroom tv/Roku and I DO have a Hisense smart TV in there. I've gone through all the remote setting and removing and re-adding the original Roku remote (Roku ultra 2018) I even bought the new Roku Voice Pro and have paired it more than once, because it's doing the exact same thing.
And just like yours all the features of the remote worked before. I.e. power and volume up and down with no issue since we bought both the Roku and tv (Hisense Android 58" 2019)
So it's not like it can be said that it's not compatible. All other features of both remotes work. The Voice Pro remote has extras features and they all work.
It doesn't make any sense. I'd really appreciate some help from Roku!!
The same thing is happening with out master bedroom tv and Roku remote and we have even upgraded to the Roku Voice Pro remote today and gone through the pairing steps multiple times and still have no volume or power control but everything else works.