I created 2 booking types - one is for a 4 hr session, and the other is for an 8-hour session. They are tied to the same sub-calendar, which I created in my Google calendar. I have done this because I have 6 different rooms, and each room takes a 4hr or 8hr session each. However, for each room the 4 hr and 8 hr sesisons tied to the same sub-calendar conflict. I turned reading calendar and also off and in both cases it is the same result.