Duplicate Registration for Same Webinar

Has anyone been experiencing the need to register twice for the same webinar? I hosted a webinar earlier today and found out that one or more of the attendees were required to register twice to actual join the webinar. In addition, I joined a separate Zoom webinar through a different company shortly after in which I had already registered, which is why it was on my calendar, but when I clicked the link to join was required to register again. It's really a bad user experience and I'm concerned it will deter people from joining in the future. 

Is there some kind of setting within the setup that needs to be checked/unchecked? This is the first time I've run into this issue and I've setup and hosted many webinars via Zoom. Any feedback is appreciated. Thank you!