Menu Disappears

I’m having a major issue with the HighEnd theme. There is a point between where the menu appears in full on the top and where it becomes the hamburger menu in which it completely disappears. This especially a problem on smaller laptops, or when people have smaller browsers open.

Please help me fix this as soon as you can. I saw that you responded to a similar question, but that it was solved by you privately sending the code to the person who asked the question.