Channel Manager

I have just set up my new Beds24 channel manager and I've noticed on my Booking.com calendar that available days have a small grey triangle in the corner of the calendar day and when I hover over it, it says "has restrictions".  Beds24 tells me that this is a Booking.com issue...can someone help explain why this is?  Also, some of the bookings on the calendar also have the number "1" on them when they are booked or "blocked". Thanks for any help.