I searched on the site and the internet and found nothing that remotely comes close to this weird issue.
We have user A who is the delegator of his calendar to user B the delegate. User A's calendar always shows the correct calendar items with no issue. User b occasionally will see the non-recurring meetings in user A's calendar disappear on her screen. The odd part of this is, when she clicks to the next day and then back again, the meetings reappear with no issue. This only happens with non-recurring meetings.
Both users are completely aligned to Microsoft's recommended settings for version of Outlook and all delegate best-practices. User A doesn't even receive his own calendar items, only the delegate (user b) does.
Any help here would be greatly appreciated as we are completely at a loss.