Reproduction steps:
1. Import the attached custom package "VFX Graphical Artifacts.unitypackage" into an HDRP project
2. Drag and drop the "NeraBlocks" VFX into the Scene view from the Project window
3. In the Inspector window Edit the Asset Template
4. Observer the flickering graphical artifacts either in Scene view or Play Mode

Expected result: flickering graphical artifacts do not appear on a VFX
Actual result: flickering graphical artifacts appear on a VFX

Reproduces on: 6.9.2-preview (2019.2.21f1), VFX Graph 7.1.8 (2019.3.1f1, 2020.1.0a22)
Could not test with 2017.4 due to package not existing and 2018.4 due to package related errors in the Console

Notes:
-Reproduces on Windows 10 and macOS
-Reproduces in Build
-Reproduces on HDRP and URP
-Does not reproduce if Update Particle is connected to Lit Cube Output
-If the camera's and the Visual Effect's X and Y axes are 0 the graphical artifacts become more apparent
-The graphical artifacts are most prominent in the Inspector window VFX preview