Post count: 2759
hi nursebibi,
1. it may because video encoding format. if you are using HTML 5 video, you will need to create video with right format like this page : http://stackoverflow.com/questions/21124885/html5-video-not-working-in-ie-11.
2,3,4. i only find this problem on chrome, i will take a look about this problem.
for moment, can you try to put your video on youtube and use youtube as video background instead, it will save your bandwidth alot (i see your video sie is more than 3 mega, which is very big to load for web server). it may also fix the problem.
Thank you