Valve Index thumbsticks always return 0

I’ve been developing a VR game for a while now using the Oculus Rift and everything was working well.

Yesterday, my Valve Index arrived and after setting it up (and plying a few hours of HL:Alyx), I tested my game in it.

I set up all the Index controls in Project Settings->Input and everything works except the thumb sticks?

I’m using C++ and have the inputs mapped set up in SetupPlayerInputComponent() like so;

PlayerInputComponent->BindAxis("MoveForward", this, &ASSLLCharacter::MoveForward);
PlayerInputComponent->BindAxis("MoveRight", this, &ASSLLCharacter::MoveRight);

And my move functions are declared like so;

void ASSLLCharacter::MoveRight(float Value)

void ASSLLCharacter::MoveForward(float Value)

etc…

When using the Oculus Rift CV1 or a normal game pad, the Value float variable works fine, but with the Index it is always 0?

All other buttons, A, B, Trigger etc. work fine on the Index, just not my movement sticks.

Does the Index need anything extra to get the thumbstick values?