mega menu item with sub-items not expanding in responsive mode

Hello-

We're running 3.40 of nopCommerce with the Alfresco theme.
We've just recently noticed that our mega menu isn't functioning properly when using a mobile device.

Everything works perfectly except for menu items that have sub-items. They do not expand when the plus sign is clicked. The minus sign does appear, but the menu does not expand.
I know that it worked correctly about 2 years ago, but it has been a long time since I tried it with a phone.

You can see it here: (use your phone or shrink your browser)
http://www.myfootshop.com/toe-care-products

My upgrade protection has expired so I cannot create a support ticket, but I am hoping that someone knows what can cause this behavior and will suggest a fix. Anyone?

Thank you in advance-

Hello,

sorry for the delay, this issue is now moved to the support ticket system.

Regards