Is it a mod compatibility issue?

Yes

Minecraft version

1.20

Describe the issue

Iris compatibility issue. Just having Iris installed is enough, enabling it is not needed. Tested with Quilt, may test with Fabric soon as well.

When the world is saved while looking at a portal, terrain isn't loaded on the next world load - only skybox is visible and the only possible action is looking around.

It also has a tendency to drop frames and stop all entity physics after some time interacting in proximity of the portal - mobs don't move and player can only look around.

Oddly this seems to be resolved when switching driver from mesa to zink. Might actually be an issue related to either driver or device - it was tested on a 64GB eMMC Steam Deck, I don't recall if it ever happened on my laptop as well, I can't reproduce that on it now and it might be because of its much faster loading times on SSD. Closing for now

Reopening because it started happening again and after updating to MC 1.20.1 and ImmPtl 3.1.0 I noticed Entity Culling incompatibility note. Since deleting EC the issue doesn't seem to happen anymore. I can't find any details about this incompatibility so just wanted to ask if it's what the EC incompatibility could be about? I've had a lot of hit and miss guesses and false positives (like Iris and MemoryLeakFix), so just wanted to make sure. Thank you!

Same quastion.