InstancedStaticMesh Instances seem to spawn with offset sockets

Hi, apologies if I’m just being dumb As the title says, I’ve an InstancedStaticMeshComponent using the mesh shown in the first pic with the sockets as shown by the debug sphere. Snapping to those sockets works fine and the code to add the new instance at the loc is just:

void ABuilding::AddInstanceAtIndexTransform(FName Socket, int32 InstanceIndex, FTransform SnapLoc)
{
    int32 AddedIndex = InstancedMesh->AddInstance(SnapLoc, true);
    InstanceData.PopulatedSockets.Add(Socket);
}

However, when the instance is added, the sockets for the new instance seem to be offset additionally by the size of the static mesh. The second pic is one of the sockets from the 2nd instance. Can provide other snippets and stuff if the answer isn’t something obvious and i’m dumb…