I have the same issue with the menu icon. It disappears when I exapnd the menu on my smartphone. I deactivated my Cashing Plugin, but I still have the same bug. I recently updated to the Version: 1.3.09.
I just removed all my CSS code for the class .main-navigation, but still the bug is present. I have backed up the version 1.3.08 and everything is working there as it should, but in the version 1.3.09 I’m having the issue :(.