Graphic glitches in custom game

After some minutes into custom games the graphics are glitching completely into triangles, sqaures or just blur screens. Some forms are then just black or white.
this issue then continues post game.
Once it happens the games are not playable anymore. you dont know the gold/lumber or where you are building.
This happens since last update to wc3. Graphics drivers are up to date. Game has also been reinstalled.