Engine gimbal causing stage spinning

[Elevatorcait]

Game Version​

2026.7.3.4826

Operating System​

Fedora Linux

What Happened​

I made a rocket in the vehicle editor, I launched it and everything works up until second stage burn. When I ignite the second stage, the engine appears to gimbal in a seemingly random direction and cause the stage to spin endlessly while the engine is ignited. This happens if any automatic control is enabled at all whether it's rate, prograde, etc.

What Was Expected​

The engine should maintain the desired attitude using small gimbal corrections.

Reproduction Steps​

1. Launch a multi-stage rocket (I provided my save file for the tri-core I experienced this issue with).
2. Reach second stage burn.
3. Attempt to circularize the orbit while maintaining attitude.

Reproduction Rate​

always

Additional Info​

• Save File:

 

[averageksp]

Can't recreate this.

I launch the rocket just like you said, then I get to the second stage (with automatic control) and everything works correctly, no issues. Am I doing something wrong?

 

[Elevatorcait]

Here I recorded the issue, I recorded the whole launch to show everything but the issue is shown off starting at 3:14. Sorry for the weird cropping I forgot to reset my OBS scene, but it still shows everything important. Doesn't seem like I can upload videos here so I put it on youtube unlisted: