Cannot block send file type by OTT application

Dear all,

My Enforce version is 15.5.0.17018. I tested agent version 15.5.0.17018 and 15.5.0107.1001. They cann't block send by file type on OTT application (Zalo, it like be skype or whatapps).

With version 15.5.0.17018, I have problems with block send by file type on Chrome and OTT application (I tried to block image file types)

With version 15.5.0107.1001, I still only have block send by file type on OTT application.

Anyone can help me?