Can't apply some restrictions on my property

Greetings,

I have some problems setting the minimum length of stay for my property. 

The problem is that I set the minimum length of stay of 7 nights in the calendar, but when I try to search for a period different of multiple of 7 days (week) it does non show as available on Booking (8...13 nights). For a period of 7,14,21,.. days there is no problem. I would like the guests to be able to book for a period >= 7 nights. Have I configured something wrong on Extranet?

BR.