Constantly pops up in phpBB "You have exceeded the maximum number of login attempts", how to fix?

Question

phpBB

Constantly pops up when logging in, even the first time, this phrase requires the solution of a text question. The same trouble and on standard style, ie. The problem is clearly not in the template. Where can she be? How to fix? I tried to set a different number in the admin panel for attempts, it still pops up. Don't turn it off at all.