Multiple meetings with the same link

I've had a reoccurring problem. When I send an existing meeting link/ID via a calendar invite, it creates a second meeting with the same Meeting ID and will change the existing meeting ID to whatever i've typed into the outlook subject line. 

It came to a head when we had a forum and people were apparently sat in the waiting room but I couldn't see them. I had to ask them to close the meeting and reopen the zoom again and then they were brought into the room I was in. 

In my browser, it will show the same meeting 3x in a row, when you open it shows as reoccurring and will have my invite in the attendees list. (same meeting ID)

Is there a solution? I don't want to unlink my calendar but I may have to if it continues?