Yes, even though flights go on sale at around T-11 months, the cheaper fares don't tend to appear immediately.
This is because airlines know full well there's a proportion of passengers - the "worrywarts" - who insist on booking as soon as possible, perhaps because their holiday dates are fixed and they're worried that flights will sell out. The airlines know they can charge them more in the knowledge they'll book anyway.
After a few weeks, once those passengers have booked, they'll load the cheaper fares. Which then, of course, may come down even more during sales.
So don't be a "worrywart". As far as the airlines are concerned, people who feel the need to book as soon as flights go on sale are cash cows, there to be milked dry.