Work item states suddenly numeric

We logged into an RTC instance this morning to discover that numbers instead of names appear in the work item state dropdown. At first we thought perhaps someone modified the configuration, but drilling down to here:

Project Configuration > Configuration Data > Work Items (advanced) > Workflows

I see all of the correct work item states and their transitions. I looked in the logs and there's nothing that would indicate something happening between yesterday and today.

Is there somewhere else that I should look, or a setting that might have flipped?