Confirm this issue. in T3 blank. My menu is
Home (parent)
|-Link1 (child)
|-Link2 (child)
When in Navigation Dropdown Trigger set on Click or Hover doesn't matter , the megamenu works properly: one click on "Home" opens dropdown plane, one more click goes to link. But in off-canvas menu click on parent menu item does nothing.
Looks like jquery.min.js error
Tested Firefox Chrome