[GAMEPLAY], [CLIENT] I can't pick draft game most of the time

hello, Sometimes I cant pick draft game, its is not available on starting screen. I'v got 20 champs, but today strange thing happened. I played two drafts today with no problem, after a second match, I picked another draft and I was waiting for system to find mine team and opps. Accidentally some strange warnings start to display on mine screen, I dont remember all of them, but most of them was that the there is some work on server and I cant play draft. I decided to relog, after that, draft mode was removed from mine list of available types of game. I have to say, that its completely random to me, sometimes iv got draft game available, but in most cases not.