Responsive Menu on Android 4.x

Hello,

My website is www.forte-its.com/

The issue I am facing is with the responsive menu, it would show for 1 second on the Android and disappear, I couldn't check on the Apple devices yet.

It shows proper on Android 2.3 old phone of 1 of my staff, on which I could check. But not working properly on Android 4.x

Please advise.
Regards,
Navin Mohinani

If you are talking about some galaxy device they have bug in their browser