I didn' really know where to put this, but I guess this should be alright here.
So I recently pruchased a AOC G2460VQ6, which is generally FreeSync capable, which is connected to my R9 390 through HDMI, since my DP is already taken up by my AOC G2460PF (144Hz, FreeSync), which is my primary monitor I use for gaming, therefore I don't care for FreeSync on the G2460VQ6. However, even though the G2460VQ6 is capable of putting out 75Hz, Windows won't let me go past 60. Even the Radeon Additional Settings report a maximum refresh rate of 75Hz. I tried setting a Custom Resolution with a 75Hz refresh rate, and that worked, but I really don't think that's how it's supposed to be. I'm on 16.9.1, had this issue since 16.8.2.
That monitor, according to AMD, does not support Freesync via HDMI.
Here is how it would look if it did support Freesync Via HDMI: