Default Payment Processor not used for "Submit Credit Card Membership"

As an administrator on a civi site, I would like for the "Submit Credit Card Membership" button to use the payment processor set as default.

It seems that currently it goes by order it was entered into the database. For instance, I have both an Auth.net and Dummy enabled. In this case Auth.net is checked as my Default payment processor. However, when I click on "Submit Credit Card Membership" to make a payement for a user of my site, I get the error message "Could not find user name for payment processor". This error message is only located in /CRM/Core/Payment/PayPalImpl.php:71 Which is what the Dummy processor uses (I'm pretty sure).

Once I disable the dummy payment processor, the button then starts using my Auth.net payment processor.