I have a Marantz SR6014 and stream most content through the most recent Roku Ultra. I've noticed that watching certain content I get occasional "digital interference" for lack of a better explanation. Essentially I'll get a quick flash on the screen of a digital artifact. It doesn't happen frequently and there doesn't seem to be any pattern to it. I also haven't figured out yet if it happens on all the "channels". I have noticed it on HBO and DIsney+, I believe, but am not certain if it has ever occurred on Netflix, for example (I have to pay closer attention to what I am watching when it happens).
Last night we were watching the movie "Little Things" on HBO Max and it happened around 4 maybe 5 times throughout the movie and a few of those were toward the end.
Anyway, has anyone else experienced something like this and/or have any suggestions? I guess I can try swapping the HDMI cable in the first instance -- I am using the one that came with the Roku, which I assumed would be appropriate to use with the device. I also have an older Roku Ultra that I can swap out to see if the issue is related to the device (the new Ultras added Dolby Vision and Atmos support - although I am using an HD plasma TV).