Multiselect Dropdown Not Working Properly

Hello,

I am creating a mashup with a dropdown widget that is supposed to filter the rows of my grid widget by their "state". When I used a regular dropdown, it was working perfectly and the table only showed the results I wanted. 

I want to switch to multiselect so that my users can click more than one state if they want to see results for 2+ different states at once. When I tried to enable this with multiselect, the grid widget in my mashup did not reflect the selections. 

What should I do to enable multiselect and have my grid reflect all of the user's selections? Thank you!