Found one issue in the slicers when working as dropdown mode.
When I use search field inside the slicer to type in category name and then select the name, the main box of the slicer doesn't show selected category name, but keeps showing "All" even though the graph is now following the slicer selection. That gives confusion for the users which data is presented.
Only clearing all the pretyped text from the search box and keeping the slicer selection, the main box switches from "All" to selected category.