Drop down menu not working when child theme is active

I am using the theme Simple Shop by Slocum and when the parent theme is active and the browser size is less that 860px the primary navigation menu becomes a drop down list that you can access.

I have a child theme that I am wanting to use, but when the browser size is less than 860px the primary navigation menu becomes what looks like a drop down menu, but if it is clicked nothing happens. If the browser is greater than 860px, the menu works perfectly. Looking at the html outputs of the php, the nav element containing the unordered list is there and has all of the correct list items for the menu, it’s just not visible.

I have tried changing my child style.css thinking there was a conflict there, but nothing makes it work. In my child theme folder I have a style.css, functions.php, header.php, and footer.php. I have removed all of those files individually thinking there were conflicts there, but nothing.

I am using woocommerce and two recommended plug-ins for Simple Shop theme. I have tried deactivating all the plug-ins to see if that was causing the problem, but still nothing.

I need help! Anyone have any ideas or suggestions?