Sun Shadow Quality - Aiming down scoped weapons causes graphical glitch

When aiming down a scoped weapon, I get some strange graphical tearing as shown below:

However, weapons with no scope do not appear to have this issue:

My graphic settings are all set to low, however I found that Volumetric quality being set to high made it even worse:

Messed around with my settings some more, and it seems like Sun Shadow being set to Medium was the culprit:

My shadow filtering was set to PCF as well.