iCal missing one of my calendars after import

I use iCal on my iMac at the office. Every month I export a calendar archive and import to my iCal on my personal iMac at home. I've been doing this for years with no issue. Recently everything will import and update with the exception of only one of my calendars. I can see all calendars in the list in the side bar but one. Why would only one not show? Is there a way to fix this? Running High Sierra at the office and I recently updated to Mojave at home.