mobile version of website menu suddenly disappeared

Thanks  to anyone who can help:

I just noticed in the mobile (phone and tablet versions) that the navigation menu of my website has disappeared. It's still present on desktop searches

Can someone help? Poel are unable to access much of my site, which is: 

https://couplefamilyandsextherapynyc.com/

It looks like you have a line of CSS that is hiding the mobile navigation, the display:none; I've circled here:

Hey there!

I got the same problem. Menu disappears on the mobile version. I am using the Mojave Template.

Can anyone direct me towards a solution?

All the best

Nino