How do I roll back to an older firmware version? Whatever PATCH you pushed two weeks a...

How do I roll back to an older firmware version? Whatever PATCH you pushed two weeks ago has destroyed your integration with YoutubeTV. I had a Roku Premiere that was constantly buffering. I replaced it yesterday with a brand new Roku Ultra that I hardwired to a gigabit switch. Roku networking says it is connected at ** Mbps. Still constantly buffering. YoutubeTV does not buffer on the computer at the same time. I have also done speed tests while the Roku is buffering and get *** Mbps down. I have * roku devices in my house and everything newer than the Roku * buffer at differetn times watching the same tv show. Some wired and some wireless. I have removed and added YoutubeTV back on each and a factory reset. Please do not tell me to reset or change my networking. I am running Cat * cables and a Google wifi router that is fully patched. I can monitor the traffic to the Roku through the router and see that it just randomly resets its network connection constantly. I am using wireshark to monitor. There are hundreds of these complaints out there. I will give it one more month before switching to another streaming device.