What information can I provide to diagnose an error?

Exapmle screenshot:

How to reproduce this isuue?

When the world is loaded for the first time. And randomly when moving and loading new chunks

It may be not an OptiForge issue.

I also thought so, but after conducting tests, I made sure that this problem does not occur on the bundle vanila Minecraft + Optifine

It's too randomly, and I can't track it.

strange, I have this bug occurs quite often. OK, maybe the problem is related to something else

It's the incompatibility between Optifine/Optiforge and Journeymap. It can be reliably reproduced while traveling fast in superflat worlds.

Confirm. In my case deleting JourneyMap also solved the problem of drawing chunks