Problem with flashing black screen when I’m useing the OneGuide app to watch live tv this...

No they are not 4k tv's. Only mine. On the other tv's doesn't matter what resolution I use. It flashes and black screen. On my tv no flashes on 1440p only when playing certain games and streaming it flashing black screen and no signal. But on 1440p it starts up no problem. Going through menus no problem. Playing call of duty problem.

You need to look for the OneGuide app. https://support.xbox.com/help/hardware-network/oneguide-live-tv/set-up-and-use-live-tv It's
not as prominent as it used to be, but it's the app that was used to set up being able to watch TV on the console. You'll use the Chromecast through that (I've got mine set up the same way). Plug the Chromecast into the HDMI-In port and then turn on the app.
The app will start walking you through setup. A lot of the verbiage will be for setting up a TV signal, but you can kind of ignore that. When the app sees the signal from the Chromecast you'll see the setup screen for the Chromecast itself and it'll walk you
through that.

Check this link for a possible solution:
https://support.xbox.com/en-US/xbox-one/live-tv/watch-tv-with-oneguide

support.xbox.com/.../watch-tv-with-oneguide

support.xbox.com/.../personalize-oneguide

DirecTV features are still accessible by using the factory remote. In the future things may be different. Stay tuned for future updates.

-Cheers

60mins is the max and that is not long enough. Im using oneguide to watch tv and the screen dims while watching.