How do I play a video on a texture after entering a trigger?

So I’ve done the Media Player, created the material and I know how to insert a video inside the engine on Begin Play. But I need it to play once I step into a trigger. I need the original object texture to change to the video and then change is back again once the video is finished or if I step out of the trigger box. Like when you enter a room, the TV turns on and when you leave it, it turns off (or after the video is finished) and by “turn off” I mean, return to the original texture.
This is what I did so far: The actor enters the trigger, the texture changes to the Video Material, but it doesn’t play. It just stands there in black. And the object doesn’t change back to the original texture…

You have to ask the video to play. You start the video player and then the material that you set will play as well.

To return to the material it had, you have to set the material to the old one again after it is done playing the video.