Menu Block has some issue. It doesnt get the current class page if it is nested sub menu. Single Submenu gets current item but if its 3rd level, only the parent menu has current item. Level 2 doesnt have currentand 3rd level.
Item 1 → Item2 = no issue.
Item1 → Item2 → Item3 = if current page is item2 or item 3 only item1 gets the current class. Item 2 will not have the current class. also if item 3 is active, only item1 and item3 gets the currentclass. Item 2 wont have the current class.