This obviously is not a bug. The whole point of setting a mesh to have “static” lighting is to allow the engine to precompute a bunch of stuff so that the game doesn’t have to at runtime. There is a direct tradeoff: you lose flexibility and some runtime memory and you gain more processing cycles in your game.
If you want to be able to rotate meshes without them looking bad, don’t set them to be static and don’t use static lighting on them.