Polylang plugin help - QuickFinder tab did not show up the language option

Question

I am using Polylang plugin to create multilanguage site. In Page, Post and Portfolio section, there is an option for me to select the language but in Quickfinder section, it did not show up the language section. I am using TheGem theme... http://flowmedia.vn/wp-admin/edit-tags.php?taxonomy=thegem_quickfinders&post_type=thegem_qf_item&lang=vi

Can you pls help me how to fix this?

Here is screenshot for more details:

http://prntscr.com/n5st8s

http://prntscr.com/n5stzl