The scheduled flights are sold out!?

When I saw Ryanair's "Book a flight" after a month, I was in big trouble.
It's still half a year away, so I thought there wouldn't be any changes, but to my surprise, air fares have changed drastically!! ︎
Some are cheaper, but the fares on the routes I take are significantly higher. The fare from Malta to Marseille is about three times the price! ︎
In addition, some trips in November are already sold out, and some flights on that day are gone!?
I understood that normally LCCs can be booked 300 days in advance.
A complete itinerary review is required. I also considered the reverse route.
However, for some unknown reason, there are quite a few sold outs from the end of October to November.
In the first place, the route to Greece is limited, so it was very difficult to create an itinerary, but it is a situation where it is impossible to plan at all if the route is reversed.
Search other than Ryanair, but the number of flights is small in the first place and it is difficult.
What the heck is going on in November!?
Even if I regretted thinking that I still had enough schedule, it wouldn't start. I have to consider the next policy!! ︎