As per title. This bug persists in space when at zero throttle, when landed, and even in the shipbuilder. Affected meshes are all three variants of the Slayton A-class engine meshes, and the Slayton-class engine mesh. The A-class meshes have a two-subnozzle effect mesh that behaves properly, so it would be a good reference point from which to diagnose and possibly fix.
Suspected meshes in question are in meshes\ships\modules\moduleeffects\smod_fx_enginemain_slayton*.nif (mind the regex asterisk to denote multiple meshes in the group)
Screenshot PNGs attached

Attached Files:
Starfield 2026-05-17 13-37-02_227.png
Starfield 2026-05-17 13-34-21_989.png