Why doesn't my skeletal mesh inherit the Rotation from its parent SpringArm or Camera? (C++)

Hi there, I have been trying to design an FPS character with just arms for a mesh. I have my first animated pose imported from Maya, but when I pitch the camera (ie. Mouse Y) the arms don’t follow.

As far as I can tell, the Skeletal Mesh is a child attachment to the SpringArm (I also tried the Camera). But it is not inheriting the rotation. I see in the ‘Details’ section of my character when the game is running that there is some setting “Inherit Yaw etc” but I cannot access them in C++. Also changing them by ticking the details box in gameplay seems not to fix it.

Should I manually force the pitch of the arms at the same time as changing the pitch on the MouseY input function?

How is best to handle this? Here is my CPP file.

// Fill out your copyright notice in the Description page of Project Settings.


#include "OfflineShooterCharacter.h"

#include "GameFramework/SpringArmComponent.h"
#include "Camera/CameraComponent.h"

// Sets default values
AOfflineShooterCharacter::AOfflineShooterCharacter()
{
 	// Set this character to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
	PrimaryActorTick.bCanEverTick = true;

	springArm_1p = CreateDefaultSubobject<USpringArmComponent>(TEXT("springarm1p"));
	springArm_1p->SetupAttachment(RootComponent);
	springArm_1p->AddRelativeLocation(FVector(0, 0, 70));

	camera_1p = CreateDefaultSubobject<UCameraComponent>(TEXT("camera1p"));
	camera_1p->SetupAttachment(springArm_1p);
	

	fps_arms_skeletal_mesh = CreateDefaultSubobject<USkeletalMeshComponent>(TEXT("arms_mesh"));
	fps_arms_skeletal_mesh->SetupAttachment(springArm_1p);
	
}

// Called when the game starts or when spawned
void AOfflineShooterCharacter::BeginPlay()
{
	Super::BeginPlay();
	
}

// Called every frame
void AOfflineShooterCharacter::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);

}

// Called to bind functionality to input
void AOfflineShooterCharacter::SetupPlayerInputComponent(UInputComponent* PlayerInputComponent)
{
	Super::SetupPlayerInputComponent(PlayerInputComponent);

	InputComponent->BindAxis("MoveForwards", this, &AOfflineShooterCharacter::MoveForwards);
	InputComponent->BindAxis("MoveRight", this, &AOfflineShooterCharacter::MoveRight);
	InputComponent->BindAxis("LookUp", this, &AOfflineShooterCharacter::LookUp);
	InputComponent->BindAxis("LookRight", this, &AOfflineShooterCharacter::LookRight);
}

void AOfflineShooterCharacter::MoveForwards(float val)
{
	AddMovementInput(GetActorForwardVector(), val, true);
}

void AOfflineShooterCharacter::MoveRight(float val)
{
	AddMovementInput(GetActorRightVector(), val, true);
}

void AOfflineShooterCharacter::LookUp(float val)
{
	if (invertedLookUp)
		val *= -1.f;
	springArm_1p->AddRelativeRotation(FRotator(val, 0, 0));
}

void AOfflineShooterCharacter::LookRight(float val)
{
	AddControllerYawInput(val);
}