Black Frames over Edits on FireTV

[Peakoverload]

I have a HDHomeRun Flex Quatro 4xDVB-T/T2/C Tuners - HDFX-4DT and two TV's. One TV is a Samsung and I have an Apple TV attached to it which has the HDHomeRun app on it. On this TV HDHomeRun performs faultlessly.

I recently purchased a Amazon Fire TV 55-inch Omni QLED series 4K and have installed the HDHomeRun app on it. On this TV, when I watch any TV channels through HDHomeRun I frequently find that when there is a edit on screen like changing from one camera to another or from a video clip back to the studio on a news program, the screen goes black for a few frames. It doesn't happen every time there is an edit on screen, nor does it happen every time I watch TV but it happens the majority of the time and does make it pretty unwatchable. We only ever have one TV on at a time and this Fire TV has no problem streaming 4K content from Netflix, Prime etc.

I also have Channels DVR and again this is fine on the Samsung / Apple TV but has the same 'glitching' on the Fire TV. I haven't yet tried connecting my Apple TV to the Fire TV to see if the problem persists as really don't want to spend out on another Apple TV for a secondary TV.

Is this a known issue with Fire TV's? I can't find any settings in the HDHomeRun app to change and when I've googled this problem, some of the settings that are suggested to change on the TV, my Fire TV doesn't have.

Any ideas?

[jasonl]

Check the TV settings and see if there is an option for auto framerate matching and disable it if so. UK broadcasts regularly switch between 25p and 50i to match the actual source content, and if the TV is detecting that it may be changing as well, and getting a few frames of black screen when that happens would not be unexpected.