Running Fire TV Channels app ( free Fresh Fun ) on Vizio TV

[FireTVOnVizioTV]

Hopefully this is appropriate platform for my issue: You launch the FTV Channels app, then no matter whether you choose videos or live TV, it shows about 30-40 seconds of it and then gets kicked out back to where you see the list of videos and channels, no errors.
All 3rd party apps work fine on the same Fire Tv 4k stick, only the app that comes with it is having problem. Tried all the basic troubleshooting, clear cache, reboot the app, reinstall the app, reset the whole 70" Vizio TV, still the same.
Anything else I can try to at least find out what is causing this?

Thanks.