Changing resolution creates blocky artifacts in vieport and on export

[cyaoeu]

Changing export resolution creates blocky artifacts on export. The red layer is a reprojected painted layer that was in a smart material. It happens in the viewport too when changing the resolution.
.spp is here: https://drive.google.com/open?id=1DROrAOHPo6X2Th5U3Sjyv9h5uoTdokte


(looks fine in original painted resolution of 1k but wrong when reprojected)

[Jeremie Noguer]

I was able to reproduce the issue on my side, we will take a closer look.