I am running dnn 5.6.0 and smith-cart 4.46.0
A couple of things -
I have a coupon code set up for a recurring product that provides a $5 discount. $30 - 5 = $25 the amount charged was correct $25 but the amount that shows in the recurring transaction on authorize.net ARB was the full amount. $30.
As an FYI
I upgraded from a previous version of smith-cart and it reset up my recurring settings. I had a customer submit an order and there was this error
[E00003] The element 'ARBCreateSubscriptionRequest. He successfully made the payment - twice actually - not sure what happened but the recurring flag was not set at authorize.net. I re-set the recurring settings again and did a test transaction and it seemed to work.