Cashier Response for 3D Secure Not Working

I'm facing issue with getting Cashier to work with 3D secure cards. Here's an overview of my setup -

Controllers -

public function show() // responds to GET '/pay'
    {
        return view("Payments.Pay");  
    }

    public function charge(Request $request) //responds to POST '/pay'
    {
        $paymentMethodId = $request->paymentMethodId;

        try {
            $stripeCharge = (new User)->charge(299, $paymentMethodId);
        } catch (IncompletePayment $exception) {
            return redirect()->route('cashier.payment', [$exception->payment->id, 'redirect' => route('home')]);
        }
    }

I visit '/pay' route to enter card-holder-name and card-element. Then trigger the card authentication with click of Pay button.

I receive the $paymentMethodId from Stripe, which I POST to my /pay route, handled by charge method on the controller.

Now, the try blog throws an exception, as expected and catch block is executed. This is where I am facing issue. Chrome receives the HTML from Cashier's inbuilt cashier.payment route, but it does not trigger pop-up or redirect the user. I can see the entire HTML returned as response.

I'm wondering if I'm missing out on any step. Can someone guide? I'm trying to figure this out since yesterday!