Navigation Child URLs not working properly in Mobile

Hello, First of all I like to appreciate the website that you have created and I like it very much. However, I have been facing one issue with the website navigation menu. The child URLs ie. Why Choose us, & Our Success Stories is not opening the link when I try to open from mobile. This is my biggest trouble. Please help me solve this problem as soon as possible. This is my website url: https://www.somenergysystems.com . Open it in mobile view and click the navigation Urls. Please help me as soon as possible.