Hello There,
Thanks for writing in! I am able to see the hambuger menu in your site.

Are you using CloudFlare or may have installed a caching plugin like WordFence, W3 Total Cache or WP Super Cache? Please keep in mind that after doing every updates, always remember to clear all caches when updating so that the code from the latest release is always in use. This will help you to avoid any potential errors.
Please let us know how it goes.