Recurring Contribution marked incomplete and no receipt sent but card is charged
There needs to be a silent post URL inputted into Authorize.net


  CiviCRM will need to be notified of the success of recurring
  contributions via a Silent Post URL. Within CiviCRM, get the ID number
  of your payment processor by looking at the URL of the form for
  editing your payment processor: it should read "&amp;id=" followed by a
  number. That number is your ID. Within Authorize.net, go to Account >
  Settings > Silent Post URL (within the Transaction Format Settings
  section). On that page, enter the URL (the following examples are for
  payment processor ID 2):


Drupal: https://yoursite.org/civicrm/payment/ipn/2

Joomla!: https://yoursite.org/index.php?option=com_civicrm&amp;task=civicrm/payment/ipn/2

WordPress: https://yoursite.org/?page=CiviCRM&amp;q=civicrm/payment/ipn/2



  If you fail to do this, one-time contributions will succeed normally,
  and recurring contributions will be processed successfully by
  Authorize.net, but the contribution status will be stuck at Pending.




Source: https://docs.civicrm.org/sysadmin/en/latest/setup/payment-processors/authorize-net/