Shadow Artefacts (Cinematic Render)

Hi guys,

I need to create quite a heavy render - rendering landscape with forest in a distance, with realitime shadows. I cannot get it working properly, the shadows have really small resolution and they keep kind of popping in (visible in the video).
I tried lot of console commands but with no avail.
[Here is the Youtube Video][1]

Can anyone help me with this?

After hours of searching, I found the issue. It was near clip pane setting in the preferences.