Not all email accounts in Calendar

I'm on outlook 365 Mac.  I have 5 emails (in my email account) but only 4 of these emails are in my calendar tab (event).  There isn't a option anywhere to make this 1 email to be visible in the calendar tab.  I can see events if I search them.  I was on a call with microsoft support this morning and we were getting nowhere even though he was very patient and was trying very hard to figure this out.  I just deleted the email account and reloaded it, but it still doesn't populate into the calendar tab.  If I go into accounts under tools you would think if I clicked on to the account there would be an advanced button but there isn't.  You would think that there would be a place to show what you want to see from each email like if your email address removed for privacy reasons you don't want to show todo's the there should be a place to check a box.