Starting in Sodium 0.6.0 beta.1, pistons/sticky pistons will briefly flicker while extending or retracting. This also applies to blocks pushed/pulled by the pistons. While extending, the head/arm of the piston and block it is pushing will not render for one frame. While retracting, the whole piston and the block it is pulling will not render for one frame.
Use Sodium 0.6.0 beta.1 or beta.2 on Fabric 1.21 or 1.21.1. (I have not tested NeoForge.)
Enter a world and place a sticky piston. (Placing it in any direction should work, but I mostly tested it facing upwards.)
Place a block on top of the sticky piston.
Use a button or lever to power the piston. To see the bug in full effect, the piston should be powered on and off slowly, as spamming it seems to lessen the flickering.
The flickering should occur. Lowering your game framerate may make it more obvious.
Repeat the above steps, but use Sodium 0.5.11 as to compare it to Sodium 0.6.0. The piston flickering does not seem to occur in 0.5.11.
Bug Description
Starting in Sodium 0.6.0 beta.1, pistons/sticky pistons will briefly flicker while extending or retracting. This also applies to blocks pushed/pulled by the pistons. While extending, the head/arm of the piston and block it is pushing will not render for one frame. While retracting, the whole piston and the block it is pulling will not render for one frame.
Example video (taken at 60fps):
https://github.com/user-attachments/assets/bf59e741-70a5-46df-8b0d-3496d9635489
Reproduction Steps
Log File
Uploaded in case you need extra information https://mclo.gs/PwZcEDt latest.log
Crash Report
Uploaded in case you need extra information https://pastebin.com/a3ALha73