Operating system: Windows-10-10.0.17134 64 Bits
Graphics card: GeForce GTX 1080/PCIe/SSE2 NVIDIA Corporation 4.5.0 NVIDIA 417.71
Broken: version: 2.80 (sub 71), branch: blender2.7, commit date: 2019-05-20 22:03, hash: rBe78770039397
Short description of error
EEVEE's viewport goes from clear to a smeary oil painting when using Volumetric shader in the World settings.
Exact steps for others to reproduce the error
Load the attached scene.
This is a simple ground plane with a bunch of trees instanced over it using a particle system.
The world uses an HDRI image combined with a Principled Volume shader to add environmental fog.
Switch to Rendered view.
Frame 0 of the animation will look normal.
Play the animation.
By the end, the viewport will appear to melt and swirl into a blurry mess.