It may depend on how they have removed the block which is preventing you from purchase, and whether or not there is any other block that is activating.
If they have added your member ID to their block exemption list, it should bypass any and all blocks they might have in place, but sometimes if they just remove the block from the listing, something else can kick in (eg phone verification, UPI strikes), or they may still have the location on their exclusion list, which often will still prevents purchase even if they add postage options to Australia.
