Trello – How to Set or Clear Default Card Description

When I create a new card in any of my boards, the card has unsaved edits already posted into the description of the card. This description is from a card I created, once upon a time, but it now gets added by default to every card I create.

This seems an awful lot like a bug, but I suppose it might be a feature.

Here is an example:

My questions are:

1. Does anybody else see this behavior?

2. If this is a feature and not a bug, how do you turn it off (or clear out the default description)?

I've looked around at as many of the board settings as I can find and I've Googled around for any insights into this, but all to no avail so far.