How to stop server side sync of recurring appointments to resend to contacts

Hi all,

Our organisation recently moved to an online exchange which means we began rolling out the Dynamics 365 app for Outlook.

Previously we used the older COMS addin which allowed users to track recurring meetings but the older plugin was quite clunky.

Recently we've had a user who was transitioning from the older COMS plugin to the new App and I did a server side sync of appointments so that I can then install the new app. The problem was that then all her cancelled recurring appointments in Outlook started resending to all her stakeholders and reappearing in her calendar.

Is there a way to stop this and what is the cause of this issue.

Kind regards,

Michael