Hello @jiaqi0412
Hope you are doing well.
I have checked your site and noticed that one of the classes that Trigger the Submenu or Megamenu to open, isn’t getting added on clicking the Menu Item. That is why the Megamenu is not showing on Mobile devices. It could happen due to the static File Optimization features enabled on your site. Will you please disable the file optimization feature of the Nitropack plugin and then check if the issue still persists?
If that doesn’t solve your issue, then please allow us to inspect the issue properly from your end. Please create a support ticket at our support center for further inspection. You will find the link to our support center on the USEFUL LINKS section of the Plugin Details page. Our dedicated support team will check the issue properly and let you know an update as soon as possible.
Looking forward to your response and we are always here to assist you.
Best Regards,
Prosenjit