I recently (January 2018) bought a Roku Express, model 3900X. It is on software 8.0.1 Build 4042-51. I have it hooked up to my TV (a Samsung UN55FH6030FXZA, running the latest (only?) firmware) via hdmi through a Yamaha HTR-3066. Occasionally the TV will drop the video signal for a second or so and then bring it back up, with the source info displayed in the corner, as if it searched for the signal and found it again. Audio keeps playing through this, I guess because it's coming from the AVR, not the TV. I have not been able to recreate this on 720p, only 1080p. Plugging the Roku directly into the TV seems to fix it, but I don't consider this an acceptable solution as I don't have a good way of getting the audio from the TV back to the AVR. I have swapped HDMI cables, both the one going from the Roku to the AVR, and from the AVR to the TV. I have tried multiple inputs on the AVR and the TV. It only happens with the Roku, as well. Neither my cable box, nor any of the three computers I've had plugged in have ever exhibited this problem.
Per suggestions on these forums, I have disabled 1-touch play on the Roku, and turned noise reduction to "high" on the TV, both to no avail.
Update: I upgraded my Roku to build 4069, which seemed to have fixed the problem, but I didn't watch for long enough to know for sure. Since then, my Roku downgraded itself back to Build 4042, and now the issue either has returned, or it never went away at all. The screen went out probably six times over the course of about five hours of football today.
It happens on every channel I use, Playstation Vue, Amazon video, and Pandora, as well as on the home screen or screensaver, so it isn't a channel issue. Again, this has only happened with the Roku, never any of the other four devices I've had in this system, all connected the same way.
So does anyone have an idea what I should do about this? Is this something I should wait for a firmware update for? Should I be trying to get a replacement Roku? If this is the same issue reported in the thread I linked above, then I should probably be ditching the Roku completely since it doesn't seem like it's getting fixed.