Booking events

When providing times in gmail for a customer to book an event using the Calendly plugin for Google, I often run into issues where a time is unavailable.  I have checked the days/times and there are no events listed nor do I have anything marked as “busy”.

I have received the troubleshooting and when clicking on the reason why the hour isn’t available it says:

CALENDAR - This time slot overlaps with a busy event on your Google Calendar

Has anyone had this happen and hopefully has a solution? TIA