Video not playing under IOS

i’m using the html5 Tag ‘video’ for showing videos like this:

<video src="user/pages/01.home/_referenzen/p049_imagevideo.mp4" controls="" poster="user/pages/01.home/_referenzen/p049_imagevideo_vorschau.jpg">
                Ihr Browser kann dieses Video leider nicht wiedergeben.
            </video>

it is inserted in a modular page and is fully functionell.
But when i use the same code to insert it in another page, no modular page. The video is not playing on any IOS devices but on other devices and other systems.
So same video, same code but other pagetype–> fully functionel to not working on ios.
Has anybody seen this behaviour and got a workaround for it?

Really no one who knows this problem and the solution?

IMO

1. Too little info provided
2. Maybe not many here use iOS
3. From what's provided, sounds like not a Grav issue

@tarudeone,

To complement @Karmalakas...

Many iOS users on the web who are complaining too.