Public Calendars Not showing any appts

I am admin of our Exchange Server. I created all the public calendars (set up as an owner of all). Suddenly I can’t see any appointments in 80% of the calenders. Nothing shows for me no matter what pc I signon. We use these also for conference room schedules. I ran the run command “Outlook /cleanfreebusy” on my pc and it cleared up my own calendar. Please help with any suggestions you might have.