Bug when the page is loading


Open this page https://info.smunch.co/home-page-new
using the resolution of 360px x 450(mobile version of the page).

Try to see the page in the mobile version, there is a hamburger menu aside and is loading fine. But when it loads you can see the menu very fast(when the page still loading) and its happening JUST in the landing page(no in the preview of the template, what its very weird). So, for sure I don't want this happen, the menu suppose to load display off by default. I don't know how to solve it.

I can provide any additional information about the code if you needed it.
Thank you.

Attached you can see exemple of the problem.