When using landscape in ue5.3 in VR mode, the landscape mesh flicks and the bottom is visible. What should I do?

When using landscape in ue5.3 in VR mode preview, the landscape mesh flicks and the bottom is visible. What should I do?

Anti-aliasing is done by MASS.

This is an old thread, but I happened to run into this just recently and found a fix – I was able to resolve it by setting the Scalability setting for Global Illumination to “high”