[Possible bug] Woocommerce Bookings Buffer after every block

I work as a private tutor. I want to add a 15-minute buffer after every session to allow me time to compose a detailed write-up for my students. Unfortunately, it looks like there may have been a coding oversight on the part of the developer who wrote the plugin. It adds a buffer to the blocks, not to the bookings. I have 15-minute blocks. If I add a 15-minute buffer, it only allows students to book on the hour or on the half hour, not at 15 or 45 minutes past the hour. If I change it to, say, 5 minute buffer time, then students can only book on the hour or at 20 or 40 minutes past the hour. Obviously, if someone wants to book a one-hour session, I don’t need a buffer period between every 15 minute block of the session.

Is there a setting I need to change for this, is the code just bugged, or is the code intentionally written to do something insensible?