I'm confused. Looking to redeem 4 x J SIN-SYD 1-way in mid October 2023.

There is a lot of availability every day throughout September and into the beginning of October... but after 2 October there is nothing. Not a single award seat on any flight for a whole month (and there are 4 flights a day on this route). Still plenty available in Sept.

Any ideas why award availability would have suddenly completely vanished?