SCREENSHOOT ERROR - POST PROCESS VOLUME

Hi! This is my first time here, i’ve a little problem with a Material…the material its work fine but the screen postition or Screensize is breaking the scene, its generate a H and V distorsion bars and i cant solve this issue…i dont understand what is going on. In Viewport this issue is not visible but when i take a screenshot, oh man, looks so awful.
Any ideas? The filter (material) is the same like this tutorial : UE4 - Tutorial - Painterly Post Processing - Kuwahara Filter - YouTube
This is the problem.

If any of you need more information, please tell me and i provide you whatever you need.

Thank you!