Description of issue:
My widget isn’t playing properly in the Player Card (where the player should be, I see a white space). I got all meta-datas fetched correctly and, strange point, I can hear audio content.
URL affected (must be public):
For some reasons I can’t give you the shared url. Here is some screenshots instead.
Cards validator, before clicking on thumbnail:

Troubleshooting steps attempted [note that we will not prioritise posts unless there is evidence of following the troubleshooting guides]:
I read all I could get on my problem, including this post which seems to be similar to mine : https://twittercommunity.com/t/twitter-player-card-will-not-play/97780
Unfortunately, no solution was given here.
Here is my meta-datas :

Any help would be highly appreciable. Thank you!