The videos on iPhone does not remember last watched position / iPad doesn't remember video playback position / Resume video on iPad where you last left off

i'm launching the website in iPhone & iPad mobile browser like Safari / Chrome, the web site contains videos.

i'm facing the issue while playing the video as mentioned below.

1. In iPad – video starts over from beginning, does not resume from where the user left off.

2. In iPhone – Video Resume is working by default

3. Then why is it not working for iPad device ?

Note: Video Resume is working by default in sandbox org but it is not working as mentioned in 1,2,3 points in Production org.

here sandbox org & Production org mean just website url like

"sandbox.myconpany.com"
"production.myconpany.com"

Please suggest what might be the issue ?