The 'Click to enter Fullscreen' button does not work for Facebook Videos (Twitter, YouTube and Vimeo are fine) that are linked in a post to the Event Stream (propbably any stream).
You are most welcome. Glad to hear that your issue has been resolved now.
Just for your information, I have locked and marked this thread as resolved to avoid confusions in the future. Please start a new thread if you have any other issue in the future so it will be easier for us to manage your inquiries.