Can't set static mesh from imported asset

I did the Programming Quick Start guide. I’m just trying to change the asset from the starter content cube to a custom one I imported from an fbx. I imported the asset and changed this line :

static ConstructorHelpers::FObjectFinder<UStaticMesh> CubeVisualAsset(TEXT("/Game/StarterContent/Shapes/Shape_Cube.Shape_Cube"));

to this :

static ConstructorHelpers::FObjectFinder<UStaticMesh> CubeVisualAsset(TEXT("/Game/Meshes/rock"));

It compiles, I even put a debug message in the Succeeded block :

if (CubeVisualAsset.Succeeded())
{
	UE_LOG(LogTemp, Warning, TEXT("Found the static mesh"));
	VisualMesh->SetStaticMesh(CubeVisualAsset.Object);
	VisualMesh->SetRelativeLocation(FVector(0.0f, 0.0f, 0.0f));
}

that I see when I drag and drop my C++ actor in the scene :
image

but the visual is still a cube, instead of my own mesh. What am I missing ?

This fixed it :

static ConstructorHelpers::FObjectFinder<UStaticMesh> CubeVisualAsset(TEXT("StaticMesh'/Game/Meshes/rock'"));