@mpcdesign, AutoPay is designed to take the money at the end of 'Payment' day, if you haven't already topped up otherwise. I've been signed up on AutoPay since the summer of 2016, and it has not failed for me other than on a plan change from a 30-day $42 cycle to a 90-day $120 cycle.
EVery 90 days, on my 'payment date, I do absolutely nothing with Self-Serve. The payment used to happen around 9 pm ET but now doesn't happen until about 2 am the following morning. AutoPay takes the required amount from my credit card, without my interaction. Every time.
Once, this past year, I manually topped up ahead of a scheduled 'System Maintenance' as it was going to be done during what is my regular payment cycle. I topped up fully prior to the payment date so that I would not have to suffer the outage that had occurred the previous system maintenance cycle to many others.
AutoPay was implemented to make remembering to pay no longer an issue. It does that more most people.
During the process - if you watch the My Account screen you will see your plan change status a few times. It's scary. However, there are messages that say 'DO NOTHING - THIS IS NORMAL' or something to that effect. It's telling you to let the system work, and do not worry about your account. It will complete.
