We have the same issue.
We have had the Roku Ultra for 3 years with no problems until recently when you would push the mute button it would go crazy turning the mute on and off and just keep doing it. This occurred with 2 different remotes and tech support had no idea what was causing this sudden behavior after years of problem free use. The thoughts were the Roku ultra box had a problem so we ordered a new one direct from Roku.
During the installation of the new Roku Ultra there were problems with the unit wanting to keep re-pairing with the remote after it already had. The pairing light on the back of the voice pro remote that came with the system kept blinking constantly. I called tech support and they had me reset the system by the method of unplugging and waiting and then plugging back in holding the pairing button when the Roku splash screen came up. This seemed to work and the remote paired up and the light on the back quit constantly flashing. 20 minutes into a movie the battery status started flashing up in the right upper hand of the screen showing a full charge and just kept flashing every couple of seconds. It stopped for awhile and started up again this time not stopping. I went thru all the remote troubleshooting tips on this site 2 or 3 times and nothing helped. I have the pro voice remote we got with our older Ultra and paired it up and it works fine. The problem is the remote that came with the new system will not stay unpaired and keeps flashing the battery status and because it has a internal battery that can’t be removed I can’t get it to stop. It keeps flashing up even on my old Roku Ultra.
We got a RMA and are returning the new Roku Ultra and today and purchased a new Apple 4K TV. Our kids have them and have had nothing but good things to say about them. It appears that Roku isn’t testing firmware very thoroughly perhaps and rolling out defective updates and tech support can’t seem to help much. We just don’t have time to deal with problems like this. I’m sorry it came to this. We paid more for the Apple 4k tv but I think it will be worth it from the reviews we have read and what our kids have experienced.
I have a hearing impairment and really struggle with understanding Roku Tech Support folks as it is based in another country and they speak in a heavy accent with broken English. My wife hears pretty good and she even struggled with it. I mean no disrespect by it at all. They are very nice folks. We just have a hard time understanding them.
I will give credit where credit is due and say it was a great 3 year run with the Roku Ultra with very little trouble while it lasted. My only wish would be they tighten up quality control because the unit we received and what others are getting should have never left the factory. I see there is no fix for this issue on the many many posts on here about the same issue.
Thank you.