Auto accept/deny not working as expected

[stuartg.orion]

I have a bunch of rooms set up with the default options including auto accept if available and auto deny if scheduled already. I have not set the conflict rules.
As an example I am trying to book a room weekly which is already booked at the same time every second week. I get a denied message for all the denies but the weeks where it should be accepted are not being accepted either. I have tried setting the percentage conflicts allowed all the way up to 100% with no change in behavior.

What do I need to set to allow all not conflicting weeks to be accepted?