Booking During Blocked Off Time

[LifeCraftCA]

Im experiencing a problem with our booking system. A networking consultation was recently booked even though my calendar was fully blocked off for the day. Please see the attached screenshot showing the blocked-off times and the scheduled appointment that somehow bypassed these settings.

Does anyone have any ideas on what to check on why this booking was allowed and advise on how we can prevent this from happening in the future?

Thank you for your assistance!

Best regards,