[blizzardreign]

So that seems to be an issue between my Fire TV and my AVR that I'll have to find a solution for, or give up and go with Rpi4. 

The same situation happens with me sometimes. Check under settings of your Firestick 4k, under Display- Video Resolution--Auto. Click through all the way to Auto, and see if there's a message on the right about how the input isn't HDCP or something like that.

If I see that message, I restart both my display and my soundbar which my Firestick 4k is connected directly to. After that, the different resolutions and modes are available to be seen in Kodi. And the display settings do not display that error message either.

I have attached some pics to explain.