Vidéo question not starting on computers in the classroom

First let me thank the team for such a great job with H5P, I've started working with last week trying several item, and i think it's great

But i need your lights, your knowings to solve a little problem

I made two interactives vidéos question

The first one here, made online

name is  Plic et Ploc  modified 2017/11/26 – 10:19

This one is added in a moodle page by the link given by the site

<iframe src="https://h5p.org/h5p/embed/147329" width="1090" height="674" frameborder="0" allowfullscreen="allowfullscreen"></iframe><script src="https://h5p.org/sites/all/modules/h5p/library/js/h5p-resizer.js" charset="UTF-8"></script>

The second one is made by the H5P moodle plugin ( moodle 3.3) in the site i manage

On my computer, in the moodle site, both activity are good, starting, everything is good

On a android mobile, it is ok too

But on the computer in my classroom, working with win7, it's not

With Explorer, Firefox ( have'nt tried with chrome yet) bug's

For the first one, made online, there is a line saying "video player loading" and that's all

For the second nothing is shown, really nothing ( see file  in attachement)

Firefox  and Explorer are updated

Then why these problems ? Is it because of windows 7 ?