I have an upcoming booking SYD-MEL in J on a 738(actually a connecting flight). From the time I booked until T-80, the seat map (from E/F) was showing row 1 as blocked, with the rest open for me; this is normal for domestic J, with the row 1 seats becoming avalable at T-80. In this case however, as of T-80, every seat except 3C & D now shows as blocked! Only 2 seats are shown as allocated. What on earth is the logic here? The availability shows as J4 C3 D1 U4.