Buyers using PayPal can fund payments from their PayPal account balance (if they carry one), credit/debit card, bank account transfer, or eCheck. The banks process an eCheck just like a physical paper check, so these can take several days to clear the buyer's checking account; meanwhile, the payment will remain in Pending status with PayPal until they receive the funds.
Buyers who finish checkout using an eCheck and proceed to their E-junkie thank-you page will only see a generic message stating that their order will be processed once the payment clears and advising them to watch their email for further details. Once we do receive IPN from PayPal confirming they completed the buyer's payment, we would then process their order as usual (issue links/codes, send emails, log their order details).
If you want us to process eCheck orders immediately after the buyer finishes checkout, without waiting for the eCheck to clear, you can un-tick Wait for pending payments to clear before processing in your E-junkie Seller Admin under Manage Seller Account > Edit Preferences > Payment Preferences. Bear in mind this means you assume some risk of an eCheck bouncing after the buyer has already received their link/code.