Is it a mod compatibility issue?

No

Minecraft version

1.20.2

Describe the issue

Due to the occlusion query prediction, portals are not rendered on the first frame that they become visible. This causes visual artifacts on corners between multiple portals. I have a powerful GPU, it would be nice to have a setting to disable this optimization so that all portals in the camera view are always rendered.

Compatibility mode completely disables nested portal rendering which is not usable here.

Hello, welcome back.

When Iris sharder is not enabled, the mod does not use visibility prediction for the first 3 renderings in every frame. So the visibility prediction issue will not be visible in most cases.

However, when using shaders, in IrisPortalRenderer, because that the rendering process requires some framebuffer copying, to avoid performance degredation when no portal is visible, it does some "delaying" that makes some portal invisible in the first frame.

Are you using Iris shaders?