My registration page is changing by itself?

Hello,
On my website (www.positifstyle.com), I created a register page. I renamed it "S'enregistrer" because de website is in french. At that time, the page exactly the way I wanted it (like Image 1). 2 days later it completely changed (it looks like the image 2)??? I didn't touch it or change it, my work there was done! How this can be possible?

Since I delete that "register page" twice. Every time it worked (the page looks like image 1... then the next day it change again (like image 2). It just like I was dreaming lol

Thank for the support. Regards,