We used to have no issue with this setup but some update to booking seems to have broken this:
We have services that have a 4h duration and want to offer two start time a day for these reservations a day. So we configured the service's availability with 2 ranges (10h am to 14h , and 14h to 18h) and since it's 2 "slices" of precisely 4h, so the booking page offered 10h and 14h for start/reservation time only. But now... it seems to think or treat the fact that the first range ends at the exact time the second one starts as if all of this is just one big range, and so it offers start time every 30 min from 10h to 14h.
So on these services, if someone books starting at let's say 11h, then the whole day can'T have another meeting booked for that service when it was made that way so that 2 slots where available each day. (they're used for providers coming to do product Demos in grocery stores if it helps) **See attached screenshots**