No calendar availability showing where there is availability - Leveraging buffer spacing

Problem: (1) Available time on the calendar is not showing (2) I believe buffer spacing has become buggy / is causing issues

Situation:

I have a calendar hold that offers 30-minute calls, but these calls can not have another call within 15-minutes before or after this call

In the past I have leveraged the "buffer" feature to not schedule calls within 15 minutes on either side of the calendar hold. I also set up the calendar to schedule calls in 15 minute increments. Historically this has allowed calls to be scheduled every 45 minutes, IE: 8am, 8:45am, 9:30am, etc.

Recently, it seems like the buffer times are recognizing each other, and will not allow a call to be scheduled within 30-minutes of each other. IE: a candidate schedules a call at 8am and the calendar hold does not show that an 8:45am is still available. OR a candidate will schedule at 8am and another candidate schedules at 9:30am, but there is no availability shown for 8:45am.

Is this an update in the system, or is there something else I am doing that is incorrect?

Thank you!