Last couple of weeks, I was having the issue my phone started to automatically forward meeting requests to some of my colleagues. Nothing changed to me phone. We are using Office 365.
After some research, I came upon the following problem statement send out by Microsoft: https://support.microsoft.com/en-us/help/3108249/attendees-receive-a-meeting-update-after-the-event-reminder-is-triggered
An interesting link to a community thread: https://social.technet.microsoft.com/Forums/en-US/e6cbcf55-6d96-4b15-9386-b8713fd168d0/exchange-recurring-meetings-got-forwarded-automatically-to-attendees?forum=Exch2016CM