Trial period not using "Recurring fee amount"

I have a subscription that I want to give users a 14 day free trial before charging them the "Recurring fee amount". So I set the product price to 0.00 and then configure the recurring features:

1. "Set the recurring fee amount to the same..." Unchecked
2. Recurring fee amount - Set accordingly (i.e. $6.00)
3. Start charging at 14 days
4. charge monthly

PayPal complains "Invalid Regular period. You must specify valid values for the A3, P3, and T3 parameters for a subscription."

Looking at the HTML hidden values, P3 and T3 are set correctly, but A3 was set to 0.

I looked into the code and came to this as the issue: uc_recurring_hosted.module; Line 523
$product_fee->fee_amount is always 0.

The following code snippet works though.

$data['a3'] = sprintf("%0.2f", $recurring_fee['recurring product']->fee_amount == 0 ? $recurring_fee['product']->price : $recurring_fee['recurring product']->fee_amount);

I tested this in the Sandbox and it appears to be working.

Any thoughts? Or am I doing something wrong in my configuration?

Thanks!