The "transparent shape" to prevent video forwarding doesn´t work when the video is full screen.

The "transparent shape" over the video controls is a common suggestion when the client wants the learner watch a video from start to end. I tried a shape that blocks all video controls, except the button to watch the video in fullscreen mode (see attached image). This works fine in normal view, but in full screen it doesnt work (the transparent shape isn´t even present, it seems).

Any suggestions? Thanks.