Family Calendar Sync Issues -- only syncs when we add something

My wife and I have a shared calendar on our two iphone6s. IOS is always kept up to date. We use one family shared calendar that we put all of our appointments, events, etc. I also have added my ICloud email to Microsoft outlook if that makes a difference.

Our problem is that if Person A adds an event on their Iphone calendar to the family shared calendar, it will only show up on Person B's shared calendar IF Person B adds an event to the shared calendar. To give a specific example, Person A adds eye appointment for May 25, Person B does not see the eye appointment on the shared calendar until two days later when Person B adds a contractor meeting for June 2nd. As soon as Person B clicks "Add" for the contractor appointment, a notification pops up that Person A added the eye appointment--even though Person A could have done that hours (or days) ago.

In other words, it seems that syncing on the family shared calendar is only happening when we "Add" something to the calendar.

Any ideas on how to fix?