Nav menu not showing up on iPad or iPhone

Hi ~ My Nav Menu only shows up correctly on a computer screen. On the iPad it’s functioning on the horizontal orientation but disappears on the vertical orientation. On the iPhone it doesn’t appear in either orientation. I’m using the Resonar theme with JetPack.

I already tried deactivating and then reactivating all the plugins, and removing all the custom codes in the Additional CSS but neither fixed the problem.

Here is the website: laurencarroll.net

Thanks for your help!