When I'm on facebook, I'm unable to open f.b.-videos in full-screen-mode, this anomaly occured about one mont ago, and is naturally a cause for annoyance! (When logging in on facebook via EDGE, full-screen-mode funtions as normal!)

Attached; Screenshot of a f.b.-video clicked for opening in full screen - and this is what happens; The f.b. 'Chat-tab' effectively blocks the 'underlaying' 'full-screen' button! . . . . . .