Hambuger menu wont collapse after click on mobile view


Iam Beta testing my new Wordpress site but there is one thing I cant customize to fit my needs. Its the Hamburger menu which appears on mobile view.
I have searched the whole day and I believe I have read all topics on that problem, resulting in me trying to add code snippets into additional CSS and the navigation.js file with no luck or coming closer to solve the issue.
I want to have the Hamburger menu to collapse if i click on a menu item in the menu on mobile view.
Its a one page site with 5 menu items which are anchor links to jump to specific parts on the site.
Any help is much appreciated!