mobile menu hamburger now a square

All of a sudden my mobile menu is not working, its just a square instead of the hamburger. Any idea why and how I can fix it?

I figured it out. I added this code /*font change to all elements*/ *{ font-family: Lato!important; }

To change front page font. Doing so gives me a question mark or a square depending on what font family I select. Is there a better way to write this code that changes the font without impacting the mobile menu??

Hi there,
Thanks for writing in.
Relating to your query here, could you kindly provide us with a link to your site so that we can have a look into this.

I look forward to your reply.
Best Regards,