I have build a new website , I put the video in home page "Desktop " , then I put the same video on mobile and tablet layout but the video not working on tablet and phone .
Please note that I used widget to put the video
As I understand that you are using selfhosted video? In order to make it work on a tablet and a smartphone, you need to have a serious knowledge of web programming. Just use vimeo or youtube instead selfhosted video.