Interactive video: VO focus stays on page in background while in full screen
Reproduce:
1) Open examples from H5P webpage in Safari on Mac
2) Navigate to interactive video component
3) Turn on VoiveOver (command + F5)
4) Use keyboard navigation to focus on the interactive video frame (control + option + arrow keys)
5) Enter the frame (control + option + shift + down arrow)
6) Change video to full screen
7) Try continuing to use arrow-based keyboard navigation to access video controls
8) Try using shift-based keyboard navigation to access video controls