No media file thumbnail and does not render

Hey Everyone, I am trying to use WD Passport wireless Pro to store my video files and use it as primary device to edit the video files using LumaFusion. I tried to access the files via mycloud app, The video files does not render and just shows the first frame of the video. Scrubbing through does not help. I thought it could be sync issue so gave it a day but still does not play the videos smoothly. Please help.

Is the format of the video supported by both the drive and the app?