Appointments on the half hour are no longer showing on my booking page

We have also experienced this problem today which only affected group appointments with a start time of 16:30 even though there were spaces still available. These appointment times had disappeared completely from the booking page for the customer whereas everything else was bookable as normal.

Extending the maximum lead time showed that this problem even affected future days, without any other bookings yet. I didn't make the connection that the problem was only affecting appointments on the half-hour mark until I saw this post.

A potential workaround that has helped us to solve the problem (although it may not be ideal for everyone) is to just change the time increments to be 1 minute:

The rest of our settings for the service have a set duration for the appointments (4 hours) which is connected directly to an exact start (16:30) and end time (20:30) for each day, meaning that there is only ever one possible start time to choose each day, so there's never been any flexibility that has ever allowed multiple time alternatives to show up. We previously had "2 hours" selected for the time increments and nothing else has changed in the settings. So changing the time increments from "2 hours" to "1 minute" has (somehow) "fixed" the problem for us and the 16:30 appointment time showed up again - even though it shouldn't really matter what value is in the box for the way that we are using Bookings.

I don't think it makes much sense logically but it works for us so I just thought I should share this information in case it could be a possible solution for other people as well.

If you need multiple times to be available in a day then I reckon you could use the availability scheduler to set the exact times that you want someone to be able to book. But unfortunately I can't really test this concept further. I have a second bookings calendar which I use for tests but the half-hour problem doesn't happen there and I can't find a combination of settings which replicate the problem.