Retro City Rampage DX filtering

[ZeroX4]

here is video




in around 30 sec of this vid you can see player on the left side of screen and till that moment filtering works fine and then it start flickering
like from filtered to not filtered image

and when game starts there is no filtering at all

i am able to bypass it by enabling
texture filtering > nearest
screen scaling filter > nearest
postprocessing shader > 5xBR

but when i load state or new screen appears or i go to menu it still flickers for few secs
in menu it flickers all the time

any1 know fix to it?