Help With An Overscan Problem


Hello guys,
Im experiencing a strange problem with rendering an overscan inside Nuke. Im working on a mattepainting, which requires some plate extension to the left and up due to camera movement, and therefore it requires an overscan. Movement and projection itself works fine, but if I view my result in full resolution, it crops out everything that is not visible on the first frame - other words, it does not show the overscan area, however, if I use downrez option in viewport, missing parts shows up correctly… I cant understand this… If it was only preview problem I would ask you, but the issue remains also on final render.

Attaching screenshots so you can check it out:

correct display with downrez of 4

incorrect display at full rez

Any help is appreciated!