Hey @GBIUA75614 - I understand this is confusing and I am sure we can get it worked out!
First of all, there always has to be a start time increment set for your event type because this is what tells the event how much time there should be between bookings. You cannot remove it/turn it off and you must choose the amount of time that you wish to have between bookings. So, if you’d like your event to start on the hour, choose “60 minutes” and so on.
As for the “OVERLAP” message - this means that the start times that are not showing up aren’t available due to another Calendly booking taking place in an overlapping manner. If you head to your “scheduled events” tab in your account you should see whatever bookings under “upcoming” that you have that are blocking off those start times. The only way to then open those start times up is to cancel the bookings already taking place, as Calendly does not allow overlapping events. In other words - everything is working as it should. Those times aren’t available because you are already booked at those times and cannot be booked twice! =)
Hope this helps!