@Betsy13
Custom settings do not act as if there is a "wall around it ".
The values (like minimum stay) which are active on the check-in date are used for the total booking.
On June 9 and 10 your minimum stay is set to 3 nights, so a booking for 3 nights is allowed form those dates. To prevent having bookings going into your 7 nights minimum period, you need to limit the check-in and/or check-out day around the adjecent time period.