Autopay did not work this month

Hi! I have autopay set up to draft on the 18th of every month. I usually received an email on the 19th, early in the morning thanking me for my payment. Since I enabled it, it has worked.

However, this month it did not. It did not go through on October 18th and when I log into my account it still shows the payment will be made October 18th. Obviously, it’s not the 18th anymore and I did not want to risk a late payment…so I made a regular payment. I enabled autopay for a reason and it’s unfortunate that the auto payment was not made this month.

Why didn’t it work this month? How can I ensure it works in the future?