I have a RX 580 running Adrenaline 18.8.1 on Win 7.
The problem: I used FRTC to limit the framerate to 30 FPS as the remedy to eternal loading in the misiion "Momma's boy". After I completed the mission, I disabled the FRTC, but still stuck with 30 FPS (according to the Overlay).
But now, after some testing, I found out that I have opposite problem: FRTC in the game profile does not apply, while does work globally. Also AMD Overlay start to flicker weirdly in the first case.
Any version prior to the current 18.8.2 has a bug with FRTC..or Game Profiles as a whole. They stop working and the application defaults to the Global setting.To fix it, enable 'Histogram' in the game profile.