A multipleDropdownField that depends on another multipleDropdownField's choices is not updated dynamically

Hello community, I have a problem with multipleDropdownField component that should show the list of options depending on the list of selected items in another multipleDropdownField. I'm using load() with nested with() for the grid component (see the code). There is also a function that returns that list of options and taking the other options (selected from the first dropdown) as arguments. The function itself is working fine. The second dropdown is updated once, when I choose an option from the first dropdown. But it never updated again when I add or remove selected items with the first drop down. Source code: http://txt.do/1sluv