Physical animation - set physics enabled doesn't set physics enabled

Trying to get some physical animation when reacting to hits. Tried the following C++ in the character class:

// constructor
	PhysicalAnimComp = CreateDefaultSubobject<UPhysicalAnimationComponent>(TEXT("Physical Animation Component"));
	PhysicalAnimComp->SetSkeletalMeshComponent(CharacterMesh);
	PhysicalAnimComp->ApplyPhysicalAnimationProfileBelow(TEXT("pelvis"), TEXT("HitReact"), false, false);

// separate function
	if (CharacterMesh)
	{
		// ensure root not hit
		if (HitBoneName == TEXT("pelvis")) HitBoneName = TEXT("spine_01");
		CharacterMesh->SetCollisionEnabled(ECollisionEnabled::QueryAndPhysics);
		CharacterMesh->SetAllBodiesBelowSimulatePhysics(HitBoneName, false, true);
		CharacterMesh->SetAllBodiesBelowPhysicsBlendWeight(HitBoneName, .5);
		CharacterMesh->AddImpulse(HitVelocity);
	}

Also tried the following in BPs:

In both cases, I get the error "mesh (bone name) needs to have physics enabled to add impulse.

I have a functional physics asset set on the character mesh and a standard collision capsule with collision set to physics only.

Any help much appreciated.