Stuttering graphics with VSync on

So I’m working on a 2D game, I haven’t gotten far in, but one glaring issue I’ve noticed is when VSync is on, my game stutters horribly, when I turn VSync off it goes away (but I’m sitting there rendering 5k frames a second). The issue is mostly visible when moving horizontally (think super mario)

Does anybody know what is going on, or how to fix it?

I Have also this kind of problem with my best computer (and not with my cheap portable) .

If i deactivate Direct3d 11 in PlayerSettings. The stutters disapears…

Would like to use direct3d11 but those stutters are horrible… I hope this will
be fix someday… And don’t know much more about it…