I've created several cards in a Trello list and am not able to assign them to team members, whether it be by using the "a" keyboard shortcut (nothing happens) or by clicking on the card and then clicking on assign (nothing happens). If I move the card to another list, I'm suddenly able to assign a team member to it, and then I can move it back to the original list. But that's a pretty annoying work around. Any idea what I might be doing wrong?