Hello,
Thank you very much for choosing our theme and for contacting us.
I am checking your site and cannot catch the problem. Please describe the actions step by step on how I can reproduce? https://gyazo.com/4d3a90ad139c989abdf9bc99be3c8911
I try the menu and it works. The error may be caused when you enter not a valid value, for example, the field assumes the number and you enter a word. Please check all the settings.
Best Regards