I had the same issue and same gpu just after clean installing Windows 10 Creator's Update, and the problem was that my TV was defaulting to "Disconnect this display" instead of "Extend desktop to this display" in Window's Display settings (right click on desktop > Display settings). My monitor didn't have the same issue. Not sure if this is the same issue you're experiencing.
If that doesn't resolve the issue, is Radeon Settings recognizing that the TV is there? Is Display settings recognizing the TV? If so, what resolution is it showing up as -- is it correct? Also, what type of connection are you using, what other displays are connected when you connect the TV -- just the monitor, or do you connect them separately?
I am using the tv as its own monitor without connecting to the computer monitor but its just a blank screen or sometime it says the screen on the tv not connected which confuses me because it worked on a very old notebook but for a desktop it doesnt seem to work right.