Hello,
Thank you for making a bug report.
When you mouse over the cards they should update. In order to LOCK the card being viewed, the Ctrl can be held so that the card does not change while you move over to scroll or move the text box down.
Please try hitting the Ctrl key a few times to see it if is stuck or if something is pressing it.
Please report back if that corrects the issue or not.
Thank you!