Here is the replicable issue:
- Open the scene https://playground.babylonjs.com/#Y7STR8#2
- Press B on the keyboard, it will trigger a blur postprocess, the blur amount will be increasing until it meets 32 px and after that it will decrease until 0.
- The issue (black blinks) only happens the first time you trigger the blur process with the B key, after that it will work smoothly, you can replicate it again by relaunching the sample with the Play Icon on the Playground.
If I can help with any additional info I’ll be glad to help!!!