Unwanted Artifacts "Mirage" Effect

I have been testing the Free VR PC Demo Project called "Barney's Basement".
Using Unreal Engine 5.3

Link to download the project:
https://github.com/SentientArt/TheBasement?tab=readme-ov-file

Video:
https://www.youtube.com/watch?v=ckjSzwDe6bQ

Issue:
I am getting extreme distortions on the edges, a so called unwanted "mirage" artifact effect when using the Meta Quest 3 via PCVR, using Windows 11 and an Nvidia A6000. That unwanted effect makes the edges "wobbly", distorted and the artefacts make you dizzy.

How can I fix this?

Thx a bunch for any ideas,
appreciate it!