Meshes are not visible after adding them to an actor scene component

I wrote a Python script (for the editor) to attach a mesh to a scene component of an actor (vegetation_root_component).

• In the logs everything looks fine, but no mesh appears added to the actor
• If I move the actor in the scene, it disappears, not a good sign

root_transform = vegetation_root_component.get_world_transform()

# Transform world location to local
local_location = root_transform.inverse_transform_location(hit_location)
local_rotation = root_transform.inverse_transform_rotation(unreal.Rotator(0,0,0))

# Make a transform for the mesh
rel_transform = unreal.Transform(location=local_location, rotation=local_rotation, scale=unreal.Vector(1,1,1))

# Add a new StaticMeshComponent to the actor
sm_component = unreal.StaticMeshComponent(actor)
sm_component.set_relative_transform(rel_transform,sweep=False, teleport=True)

# Set static mesh
sm_component.set_static_mesh(random_mesh)

# Attach to vegetation root
attached = sm_component.attach_to_component(
    vegetation_root_component,
    socket_name="",
    location_rule=unreal.AttachmentRule.KEEP_RELATIVE,
    rotation_rule=unreal.AttachmentRule.KEEP_RELATIVE,
    scale_rule=unreal.AttachmentRule.KEEP_RELATIVE,
    weld_simulated_bodies=True
)

notes:

• attached is True
• hit_location is a line trace result. It appears on the mesh with a debug sphere.

LogPython: blocking_hit=True
LogPython: hit_location=<Struct 'Vector' (0x000002762A062B30) {x: -24.369755, y: -278.251794, z: 136.546713}>
LogPython: hit_actor=<Object '/Game/VRTemplate/Maps/VRTemplateMap.VRTemplateMap:PersistentLevel.Tree_Actor_C_2' (0x0000045B51E21400) Class 'Tree_Actor_C'>
LogPython: impact_normal=<Struct 'Vector' (0x000002762A0629A0) {x: -0.936350, y: 0.315688, z: -0.153591}>
LogPython: Hit: Tree_Actor_C_2 at <Struct 'Vector' (0x000002762A062B30) {x: -24.369755, y: -278.251794, z: 136.546713}>
LogPython: Random mesh: shrub_04_b_LOD0
LogPython: Added mesh component 'shrub_04_b_LOD0' to Tree_Actor_C_2