Info

Minecraft Ver: 1.19.2
Loader Ver: Quilt 0.23.1
Mod Vers:

• Iris 1.6.11
• Effective 2.1.1+1.19.2

Shaders Tested:

• BSL v8.2.08
• Complimentary Reimagined r5.1.1

reproductin steps

1. enable shader in the Iris options
2. look at a create contraption
3. cause a splash (just jump in some water)

bugged behavior

• the contraption seems to jump around the screen weirdly

expected behaviour

• it doesn't do that

Does this happen on the latest Fabric version? Also if it jumps around, please provide a video, it'll be easier to tell what's wrong

Hey I too have encountered this problem now, the contraprion doesn't really jump around, it just sort of teleports to the spot where it is at in the photo
Edit: It happens to me in 1.20.1 fabric with very little mods installed
Also I'm using Rethinking voxels' latest version (i think that's a complementary-reimagined fork) and iris' latest version

I think I know what the issue might be, does it still happen in the latest alpha?

There's no way to try that as Create is currently on 1.20.1 and not available for the newer versions. I did try this on the latest 1.20.1 release tho where the video was taken. However I've been playing around with shaders and Create for tha last week and just now tried if the Iris & Occulus Flywheel compat mod fixes the issue with effective.
IT DOES. I am happy now