Parallax effect with Drupal and Bootstrap


I followed the tutorial below to create a parallax effect on the home page of my site.

The parallax effect works very well for the anonymous user.

When I log in with a user or administrator, the parallax effect does not work and white space is displayed between the blocks.

I do not understand where the problem comes from. An idea ?

You can do a test on my site :

The user ID and password is “demo” without the quotation mark.

Drupal version: