How to reproduce:
1. Open the attached project Scene labeled "RenderingBug3"
2. Enter the Play Mode
3. Resize the Game View
4. Inspect the behavior
5. Make a WebGL Build
6. Host the WebGL Build on a local server
7. Open the WebGL Player
8. Resize the browser
9. Inspect the Player

Expected result: WebGL Player looks the same in the browser as in the Editor
Actual result: Visual artifacts are seen when resizing the browser

Reproducible with: 2019.4.23f1, 2020.3.2f1, 2021.1.0f1, 2021.2.0a10

Affected devices:
- GTX 1080 (461.92 drivers)
- GTX 660 (461.40 drivers)