I just had to create a 26 weekly payments for a payment plan and I had to click the add payment 24 times, add the same payment amount 26 times and choose 26 dates for the payments to be processed. Not only that but the calendar that pops up to choose the date stays on the original month of the first payment so by the end I had to click the arrow button 5 times to get to the right month to choose the date of the last payment.

See looms here: