Visual corruption

We have a rare bug. It happens maybe once per 40 hours of testing randomly throughout the game. When it happens, the screen stops rendering correctly and can persist even between runs. It appears to be rendering only some random tiles of the image while leaving others blank. Apart from the rendering, the game continues to play normally:

We are using Unity 2018.4.6f1 with Oculus Android package 1.38.6 and Oculus Integration 1.42

There don't appear to be any errors reported in the logs and it happens in both release and development builds.

Has anyone seen anything like this before?