orders marked as "reshipped" customers receiving double confirmation emails

Why do some of our orders get marked as "reshipped"? All we do is click the check mark on the "orders" page. Also the customer it just happened to received two email confirmations for shipping for the same order which he is not happy about... buyer #11954

How do we stop this from happening?

The email log shows that the "mark shipped" button was pressed at 2020-10-29 08:06:36 and then again 4 seconds later at 2020-10-29 08:06:40.

This is intended functionality to send the shipped email every time that you ship the item.

To stop this from happening, be sure to press the button only once.