I have a suggestion to offer for this. Instead of using payment terms on each invoice, I recommend editing the due date on the invoice. Editing the due date will override the term that is currently set on the invoice.
Allow me to explain how to do this:
1. Open the invoice.
2. Under Due date, type in the preferred due date for that invoice.
3. Then fill out the invoice as normal and click Save and close.
That's all there is to it. Please let me know if you have further questions. I'll be here to help guide you every step of the way. Have a good one!