Might it have been prior to 24-July (the date of the OP)? If it wasn't on or after that date, perhaps you were searching before the bug resurfaced.
On searches with no availability, did you see the usual
Unavailable, and the normal-width availability column, or did you see
Date unavailable for Award Booking
in an extra-wide column?
BTW, if anybody really wants to book a SA on a blackout date, now might be your best chance to do so (via phone), as many searchers may just take the web site at its word.