Bug Description

Whenever a piston retracts, it flashes, becomes invisible, and you can see what's behind.

Reproduction Steps

1. Create a new instance on Modrinth in 1.21.x (tried in 1.21 up to 1.21.8 and they all had the bug, I think it might come from the 0.6.13 update)
2. Add Fabric API and Sodium
3. Launch the game, add a piston and a lever
4. Flickering happens (check video)

Log File

latest.log

Crash Report

crash-2025-08-17_20.19.49-client.txt

The torch behind the piston is only to improve contrast.
Also I made sure to not touch a single setting when loading the game, everything is as explained in the reproduction steps.

Duplicate of #2768

I'll close this as duplicate since it seems to be the same bug as #2768, but thanks for providing additional information.

Yeah it's clearly a duplicate (for whatever reason I couldn't find it when doing a search).

Thanks for the quick feedback 👍