Room calendar multiple booking

Hello everyone,

we have the following problem/situation:
We have one office, where some students work from time to time. They aren't at the office everyday, so there are more students then workstations in that office.
So the students know when there is a space for them to work, we want to use a room calendar so they can place a meeting in there, when they will be in that office.

In the office are 3 workstations, so 3 students can work at the same time there. Our idea was to set the allowed conflicts to 2 or 3 (don't know what the right number would be).

But it seems like this option doesn't have any effect.

I tested it with my account and made 3 meetings with the room at the same time and all of them were accepted. I don't have full access to the room calendar account (took it away for testing), but it still is possible for me to overbook the room.

What settings do I need to make, so our idea can work?

Is this even possible with room calendars?

Best regards,

Thomas