Ok, so I tried all those solutions and nothing worked. I started getting curious as the battery indicator started flashing up on the screen when it was just sitting there. I am not sure of the exact model of my remote but it is the one with a headphone jack but it is not a voice remote. In 2022 it was almost 7 years old (I think). The remote uses 2 AA batteries. I also noticed the batteries were getting warmish, not dangerously hot but just warm, so I started suspecting a short or failed motion control chip. For the record, this remote did not have a motion control chip.
MY SOLUTION (and it worked!!!)
At first I knew this was not batteries as the remote in the course of a month killed a 24-pack of Duracell Procells that were only a couple of months old. My firmware was the latest version as well.
So I decided to take it apart as I have had other devices where the rubber decayed and stopped working. There is one screw in the middle of the battery compartment, after removing that I had to take a small flathead screwdriver and pry it apart. It popped apart pretty easily. There are several components inside. A circuit board that needs to be popped out, 2 rubber pushbutton modules, and 2 clear plastic "sheets" with little metal contacts that connect with the circuit board. The inside was disgusting (it was 7 years old). I cleaned the inside with alcohol hand cleaner (thank you COVID) and an old toothbrush. I wiped down both sides of the clear pads and the contacts on the circuit board. I rinsed everything and dried it out. Reassembled the remote and installed the batteries. Everything started working fine and it no longer kills batteries. It works like new even though all the buttons are worn off.
I am not an employee of Roku or its parent company or any of its subsidiaries. I do not recommend using alcohol on the parts as it can damage plastic and rubber, you can just use water and a paper towel.
I take NO RESPONSIBILITY for any damage you may do to your remote attempting this, DO NOT do this if you do not know what you are doing. I also take NO RESPONSIBILITY for anyone hurting themself. You have been warned!!!
Again, if you are not comfortable with any of this, do not do it!
If you have any questions, you can email me at vindalootiger (at) gmail dot com and I will do my best to help. If I get time I will post a link to a complete teardown of the remote.