Using Classic Outlook on Windows for personal email, calendar, and contact management
I have just run into this same issue, but with a singular meeting.
I scheduled a meeting with some members outside my organization, and ran into the conflict manager issue. I also clicked the wrong option, and now have many multiple instances of this meeting in my calendar. If I try to delete the meetings from my calendar it requires me to send a cancellation message to the other meeting attendees in order for it to be deleted. (I will not be doing this) I am the only one with multiple instances on my calendar, as my coworker who is attending the meeting only has the original instance in her calendar.
I do have this calendar synced to the outlook app on my phone.
Please let me know if any progress has been made towards a solution. I would like to delete all but one of these meetings from my calendar.