menu duplication on a small screen after using UberMenu 3 plugin

Hello,
I need help please.
On a small screens, the theme menu get duplicated. see attachment.
I am using Highend Theme By HB-Themes (Version: 2.3)
I have Wordpress 4.2.2 installed
I suspect I did something wrong when I configured UberMenu 3 plugin.
Thanks,
George