How to reproduce:
1. Open the attached project
2. Open Supersampling test scene and press play
3. First make game view as small as possible and press F10 ( it creates screenshot which super size parameter is 16)
4.Then make a large game view and press F9 (it creates screenshot which super size parameter is 1)
5. The taken screenshots are found in Data/Screenshots

Actual result: capturing screenshot Application.CaptureScreenshot has strong artifacts with cubemaps
Expected result: Screenshots quality is as good as original view

Note: the translation effect also happens for simple unlit materials

Reproducible: 5.3.6p8, 5.4.3f1, 5.5.0f1, 5.6.0a3