Invoice Reminders being sent although invoice is paid

Hi Community!

I am new to invoice payment reminders and only recently set them up.

I have had two customers today inform me they continue to receive the email reminders to pay their invoices - after they have in fact paid, and I have matched/allocated their payments accordingly.

I have checked the activity history of both invoices and can see they are correct, they have both received two more emails after the date their payments were marked as received.

What can I do to fix this or prevent this from happening?

Thank you!

Chloe