User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:63.0) Gecko/20100101 Firefox/63.0 Steps to reproduce: 1. Navigate to the video on the page - similar to https://developer.mozilla.org/en-US/docs/Web/HTML/Element/video 2. Using tab to focus on the video 3. Pressed space to play the video. 4. Then used tab to get the focus on to the player controls Actual results: The focus never goes to player controls though the keyboard shortcuts apply, the user can never get the player controls buttons focus using tabbing. This works fine on Chrome Expected results: User should be able to tab through the player controls and perform actions using keyboard This is an Accessibility concern and Firefox should handle this just as Chrome does.