This is weird IMO. We're not talking about high refresh here, 75hz is moderate and should be fine on Ryzen.
The occasional stutter from area loading, especially in open world games (note: FC5, TW3) is not uncommon even on the fastest rigs. A repeating stutter however points at a problem.
Run 3DMark Time Spy. Does it stutter?
Run 3DMark FireStrike Extreme - does it stutter?
The fact that Fast Sync reduces the stutter is counter intuitive, because as you push higher (internal) FPS, you'd expect more stutter if the CPU limited you. After all, it will not be able to keep up as well as it does at 75hz. Fast Sync is also known for the occasional somewhat longer stutter every once in a while if you cannot at least double the FPS wrt your monitor refresh rate - simply because at some point you will be out of sync briefly and its 'missing the frame' to fall back to.
Unfortunately, for the sake of finding my issue. Timespy and Firestrike run well. Firestrike does present a couple of stutters, but searching online I found those were common and in fact, both my 2060 and 1060 produce the very same stutter which occur in a couple of specific moments. Besides that, the 3dmark benchmarks run without any hiccup, thats why I am going crazy, I don't understand why I have stutter in some games and not in others, and confused because it seems the more I push the 2060, the better it behaves, where as low usage seems to be more problematic.
I am trying to overclock my ram to a higher speed and see if that helps, but I am kinda struggling with it as I have no previous experience with overclocking anything