If there are insufficient funds in your Connected Account, then your scheduled Top Up will fail and Spriggy won’t attempt to take the money again until the next Top Up date.
Your Connected Account (debit card or bank account) needs to have sufficient funds for your scheduled Top Ups to be successful.
If your Scheduled Top Up is missed because of insufficient funds, you will need to do a manual top up. See this guide if you need to submit an additional Top Up.