Flagged emails suddenly grows by 700

[David MOORE]

Has anyone else experienced this? Suddenly this week my flagged email folder went from 15 to 700+. It's showing flagged emails from more than 10 years ago. I had another colleague say that the same thing happened to her.

[#2]

We have the same case. Is there a solution/workaround in the meantime?

[#3]

@David MOORE This is happening to several users in our workplace. To the point where there are accusations of someone else having access to their inbox's and suggestions that if it isn't someone with delegate access then it must be me mucking around.

Has happened twice this week on different inboxes using the Outlook 365 client on the PC.