1 Your videocard model.
Sapphire RX590 Nitro
2. Your driver version.
3. Have you artefacts like on attached screenshots or not (answer "No, I haven't these glitches" - is very important to know too!).
Yes Ground and Shadow Flickering Below 300Ft
4. Does FXAA to MSAA swithcing solving this issue for you completely?
No MSAA Best
5. Does driver settings reset to Factory settings with choosing default GAME profile after that helps?
6. If you're using some kind of graphics mods (migoto, re-shade or something)