SlimScroll creating issue in scrolling inner dropdowns in a form

I have used slimScroll in my form and form contains multiple dropdown fields. When I load the page first time the dropdown fields item scrolls perfectly but on activating the main form scroll that is slimScroll I can't scroll inner dropdown fields. Please suggest solution to this. I have used semantic ui dropdowns.

Please suggest some solution to this if its supported in within slimscroll.