Kurylo3d, If you feel that this is a compatibility issue could you make a new post labeled: Shadow Flickering On Skeletal Mesh For gtx590
That will help people who are having the same issue find your post and get help. Once that is done we can do compatibility testing on our end to see if we can get the same problem. We will also need the dxdiag on the machine that has the flickering.
Also I’ll start investigating that other issue you mentioned.
Thank you,