[Theme : Gridsby] and Safari compatibility :S

Hello!
I currently use the gridsby theme (with few homemade adaptations) for a friend’s website (https://dourak-production.fr/).
The gallery effect on the homepage works well. I configured it with the ‘Direct link to the post’ option.
Everything works like a charm except with Safari (specially on mac)…
Here is the issue. When I click on an picture on the homepage, it load the post page. Okay. Then, if I click on the logo to go back to the homepage, the ‘masonry effect’ doesn’t execute well and the page doesn’t display all the posts (a big white <div> blocks the bottom of the display). If I don’t use a click on the logo but the safari ‘Back’ UI, the homepage never loads… It stay stuck on the loading anim…
As I’m not sure of the origin of the problem (safari, changes I made on the theme,… ), it could be of great help for me if someone who has the same gridsby theme configuration could try navigating on his site with Safari (prefered mac version).
thanks for reading (and helping).

jim