As you can see in the picture, the dates Sunday and Wednesday do not have inventory even though it is not booked. 

To prevent this, go to Settings>Properties>Rooms>Setup then scroll down to Block Dates After Check out. Make sure to put none on it.
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Alternatively, if you want to do block the dates after each booking (for cleaning purpose, etc) without manually blocking it, you can select One in this option so it auto blocks the dates every after booking without you worrying to always check your calendar.