image slider making problems on mobile view

So i'm trying to make a full screen slider (fits auto to every screen-using the VH units)

anyway it's working great on most browsers . but when i enter the website on my Samsung galaxy I get this weird problem that the : fixed menu is getting wider and thinner as the animation proceed .

another weird thing that maybe will help:

if you open the mobile menu and then close it , the problem disappears !

i've tried playing with the width (100% / 100vw) but noting helps..

here is the website:

short url: http://goo.gl/EOoXoZ

css:http://ift.tt/1HIm4Wl

Thanks in advance guys and enjoy the slider :) (work of mine and another dude who wrote a full screen slider)