I have static meshes that I want to be static in runtime, so I changed the mobility from movable to static. But when I build geometry for my level, all of the meshes are set back to movable, preventing me from doing light baking with emissive materials
Where are you setting this? By default meshes are static.
^ pretty sure by default they are “movable”, if spawned via C++ code.
https://docs.unrealengine.com/en-US/…ype/index.html
Anyway to the OP … if you attach a lower mobility mesh to a higher mobility mesh the lower mobility mesh will be auto-changed.
E.g. you attached a “static” mobility mesh to a “movable” or “stationary” mesh the static one will change. Maybe check for that?