Attendees Not Able to Access Webinar - Spinning Circle in Browser

Is anyone else having this issue? Over the last month or so, our customer service lines have exploded with registrants unable to access our webinars. When they try, the get a blue spinning circle in their browser. We've tried both Chrome and Edge. We've made sure that browsers are updated to the latest versions. We've had them try incognito tabs or windows. Nothing seems to help. Any ideas?? This is a new problem for us and we don't know how to resolve it.