[OpenGL] [Linux] [4.20] UV-Distortion in Viewport

Hello,
I get a strange Bug if i open my Project with OpenGL in Engine Version 4.20.
Some of the StaticMeshes have Distorted UV-Maps (looks like):

The material is grey with artifacts, and at the bottom it looks like a distorted UV-Map.
On some of the trees arround the UV is completely messed, while others look normal.
In the Mesh-Editor (doubble clicking) it looks fine:

(This tree is from KiteDemo) (Also happens to the Sky: Ultra Dynamic Sky in Blueprints - UE Marketplace)
This was no issue in 4.19. Also if i launch the Editor with -vulkan flag everything is fine (except the high crash rate).
The Engine is a git clone of branch “4.20” from today. I see this occur since Preview version and maybe before.

May this be another OpenGL bug, some new button i didn’t notice or a problem while opening/converting an 4.19-Project?

My System:
OS: Debian Stretch
Nvidia Driver: 390.48

Hardware:
GPU: Nvidia Titan X
CPU: Intel 6900k
RAM: 32GB

This is how the scene looks when i run the Editor with -vulkan flag:

Hello,

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Thanks