Outlook for Mac – Disappearing meeting invite, re-invite not showing up on calendar

On a delegated calendar (I'm the delegate), my boss has a recurring meeting that I "tentatively" accepted for the series on his behalf and then wanted to confirm his participation in one specific occurrence so I accepted the specific meeting.  When I did, the entire series disappeared from his calendar.  I requested a re-invite to series and have received the meeting invite on behalf of my boss.  The email indicates that he has accepted the meeting and his calendar has been updated automatically but it isn't showing up on my Outlook.  Please advise.  Thank you!