Collection Gallery section not displayed on mobile devices but visible under a Preview mode

Hi there!

Recently I received the issue that one of my gallery section (under the project page) isn’t visible on mobile devices. During the creation process we used a subdomain and everything worked well but after publishing to the main domain this section isn’t available. All other devices have this section and it loads perfectly.
Does anyone had the same issue? I would really be thankful for any help!!

*More details:
That’s a single project page. Section calls: gallery-2columns-mas:

Here is my site Read-Only: LINK
([how to share your site Read-Only link][2])