language dropdown function not working

Hi,
I checked the Languages under settings. I am testing a bilingual site. The language dropdown box does show the two languages. When I select one of the language, nothing changed as far as I can see. I have created a same event with the two languages with two different category (just for use in the two languages). As far as EM is concerned there are two events. They show as such in the dashboard Events. I can filter by category ID in event list. But I cannot do this with Language filter in WP-Fullcalendar. I think the Language filter does not work, or I don’t know what function it supposed to do.
Please advise. Thanks.