Paypal Recurring Payments behave differently to other regular payments. Unlike credit card payments which are create and charged from within Payments2Us and Salesforce, Paypal payments are generated within Paypal, and then the information is sent via the webhook and ID details to create a Payment Txn as a record for the payment.
The initial Payment Txn should be they type "Paypal Setup". This Payment Txn authorises the Paypal account to be charged.
Make sure that all setup requirements within Paypal are complete. See here for information about Paypal setup.