I upgraded to Roku player model# 4660X2 which was upgraded to OS 9.0 on 12/22. I have an OLED 4k Ultra HD TV. The flicking started almost immediately and I haven't been able to get it to stop. I tried everything I've read on this forum and have had limited success but the problem hasn't totally gone away. It's getting to be really annoying and I'd like to find a permanent fix. I'm not a techie but know this is a product issue that needs to be addressed by Roku.
This is apparently not a new issue so I have to assume it;s on Roku's radar and is being addressed. When is a solution expected?
Check under the advanced settings for the setting for framerate matching, and turn it off if it's on. I haven't had flickering, but I did have chopping playback with it on. Perhaps that's what you mean by flickering.
Dan Roku Stick (3600), Ultra (4640), Premiere (3920), Insignia 720p Roku TV, Sharp 4K Roku TV, Nvidia Shield, Windows 10 Pro x64 running Serviio and Plex on a wired Gigabit network.