Attendees Can't Get Into Meetings

Attendees can't get into my meetings - it says that the host has another meeting in progress. What the???

I start meetings from my Zoom app on my Windows 11 Pro laptop. I send out invites from the Invite link that the Zoom app gives me for each meeting. But no one can get in using that link - it says that I've got another meeting in progress, which I don't. What is going on and how do I fix this???