i would need to upload the video with 120 FPS to really show the issue, since it will be much harder to spot if the already recorded video gets downgraded. i will try to record one video with 60fps where the issue is still well visible
i don't think it's vsync related. i tried those settings (and also restarted the game for every change):
vsync via BethINI on
vsync via BethINI off, via driver on (both normal and AMD enhanced sync)
vsync via BethINI off, via high fps physics fix on
completely off, via high fps physics fix "allow tearing = true"
As far as I can tell, all the settings work "as intended". If any kind of VSync was active, there was no screen tearing at all. as soon as i went completely off, I didn't even notice the jitter anymore because the screen was tearing so much it's unbearable.
I have my graphic driver updates on manual and I definitely did not install an update in the timespan the jittering started. infact, i didn't update since the driver update for horizon forbidden west was released.
I don't even use shadow boost since I'm getting overall good fps even with ultra settings and 8000 draw distance (very rarely it dips into the 90s). But i did fiddle around with the settings a bit, and it still didn't change anything. :/
It's also definitely not resource cost related, since the jitter stays perfectly consistent everywhere I go. interior, exterior, high demand areas, low demand areas, doesn't matter.
Its also not TAA related. I tried with TAA and FXAA, the issue still persists.
Also the FPS and frametime is perfectly stable almost all the time, absolutely no hitches or anything. AMD drivers don't report any microstutters at all either.
EDIT:
I uploaded a short clip of the issue on youtube. While youtube compression makes the issue look way worse than it is, it's still very visible how unsmooth it feels (even tho it was recorded in 120 fps and is available in 60 fps on youtube). This was recorded with vsync and TAA on, and while you can definitely see the jitter, there's no screen tearing at all.
please don't mind the dude talking in the video, it's another video i played while trying to resolve the issue. i forgot to cut the audio.