Composure SUSPENDED in Play Mode

Hi,
I have a simple Media Player and is receiving video feed from camera via HDMI, On Begin Play in the Level Blueprint I open the Media Player and play. If I create a plane and apply the material it works. The problem is that when I click play composure is not working in play mode but in the Preview com I can see that it’s working… Could you help me? I’m new to this and I need to go in play mode to get the data from vive tracker.
Here’s a quick video: - YouTube