Solved Not all engines fire on the side-attached or through a decoupler "booster" tanks with an engine plate

[Denis]

Game Version​

[2026.8.22.5348]

Operating System​

[Windows 10, macOS]

What Happened​

When using an engine plate (4-pod, 3-pod, 2-pod) and side-attached tanks, be it directly attached or through a decoupler, one "booster" fires all engines, while the others only fire 1 engine.

What Was Expected​

All engines should be firing

Reproduction Steps​

1. Central tank with a 4-pod and 4 engines
2. 4x symmetry, add 4 identical tanks
3. Attach engine plate of your choice for 2+ engines to the 4 "boosters"
4. Use at least 2x symmetry to add the engines to those "boosters"
5. Launch and watch the engines not firing, and the rocket thrust being off-center

Reproduction Rate​

Always

Additional Info​

• Video/Screenshots: Screenshot attached (would add a 2nd, but the maximum attachment size is silly)

 

[Kiwi Shark]

I have reproduced this.

 

[JPLRepo]

This should be fixed next build.

 

[Denis]

Can confirm fixed in v2026.9.4.5400+. For existing vehicles, may need to remove the engines, the engine mounts, and re-add them back