Iphone 6 plus menu button as just one line

Hi, I implemented the menu and so far it's working great (I added the hack to let it srolling smoothly in iOS)

I have another issue. In both iphone 6 plus i could give a try i see just 1 out of the 3 lines the create the menu icon (the top one)

I tried both safari and chrome, portrait and landscape, without any success... work great in iphone 4 , android etc etc

BR
Duccio
