There’s this hidden woocommerce Notice message that shows up only when certain things happen. That could mean that you could overlooked this and forgot to style it to match your web style. This can still be affected by CSS.

There’s also no part in the interface where we can change the message shown when this happens, Thus We need to put custom hook to override the text. For now, the default text is sufficient, but when there’s an easier way to customized it, this page will be updated.