Jump sound

If you’re overriding a function, better do it explicitly:
void Landed(const FHitResult & Hit) override;
And call the parent function in case something is done there:

void AGameCharacter::Landed(const FHitResult & Hit)
{
    Super::Landed(Hit);
    bIsJumping = false;
}

Just to make sure everything in the parent class will work too.