The frieze in the game when you expand the window

Hello! Faced with the problem. Is that the client (MMO TERA) after maximizing the window hangs for half a minute-a minute and then, if the window is no longer minimized, everything is smooth for the passage of the frieze. However, if you re-roll it, then when you return back to get the same frieze. And so an infinite number of times. Depends only on minimizing the window (Alt + tab) or simply if you click on something outside the game window, making it inactive and then come back to it. The window to full screen disable antivirus, of defendere, firewalls/startup/services/rollback/system memory inspection - all tried. Started a couple days ago. Playing for the fourth year, it had never been. There is such a thing only with this game, nowhere else such is not observed. Support the game advised me just not to collapse, so is forced to look for an answer beyond.. Thank you!