@Iztok0
as I see you have just 1 listing and 1 calendar for 6 rooms, with 22 beds. So, if someone book 1 room or 1 bed then your calendar will show as unavailable. The way it is now it seems that you rent the whole unit with 6 bedrooms to only one group of guests starting from 30€/night for 1 guest and then 56€ more for every other person (if any) ?
Is it possible to book just one or two rooms? Or just one bed? If so, then you need separate listings for each bedroom. Or bed.
If it is possible to book just the whole 6 bdr unit then you should set up starting price for let's say up to 10 guests and then xx € for every additional guest up to 22. In that case only one group of guests will be able to book at the same time.