Bug with animations on the first section

Hello !
I have a problem with the first section of my website.
In the back-office, the animations work well but when I go to the production site, the animation is buggy: there is no fade effect as we wanted, it’s like jerky, frozen.
I noticed that on Opera, the animation is smooth compared to Chrome.
Why do we have this problem and how can we solve it?
Thanks for your help!

Here is my public share link: Page d'accueil Bleu 2