Caribbean Beach Resort the last week of September

We are a party of 5 so we are wanting to stay at CB with the murphy bed.
I am able to book 9/28 thru 10/3 but when I tried to add 9/27 to give us an extra day it says no Standard rooms are available. Only water/pool view or preferred. Is there something going on during that time that anyone is aware of? Or possibly more murphy beds being added to more rooms? just wondering.