IPInfo used to save the expanded state of the infobox to a user preference, ipinfo-infobox-expanded. This was removed in T304430: Use localStorage instead of a user preference for saving whether the infobox is expanded or collapsed (for reasons explained on that task).
A line has been left in infobox/init.js to clean up the user_properties table. This task is for removing that line, once a suitable amount of time has passed.