In testing the booking functionality and I have found that I am able to book meetings in a time slot of the current day that has already passed.
At 13:23 UTC+2 local time I was able to book a timeslot for today starting at 11:30 and ending at 12:00.
And at 13:37 UTC+2 local time I was able to book a timeslot starting at 12:00 and ending at 12:30.
It seems as if Wordpress is living with a 2 hour difference. But in Wordpress settings, the timezone is correctly set to UTC+2.
In Hivepress I had Timezone enabled for bookings. And while booking, the timezone was set to Amsterdam, which was correct. Disabling the timezone did not change the behavior.
Any advice to solve this is appreciated!