Check the membership plan allows for direct debit payments.
To do this go to the settings > membership plans > click on the plan > details tab > then ensure the payment method is setup.
If this is set up this would indicate this is due to the member sign up online
When signing up online they added the plan to the basket. They were then presented to setup Direct debit bank information.
However, they clicked off the app / back to the dashboard.
Now the plan turns overdue in the basket
when they go back to the payments they pay the overdue amount via card.