Wix Shared Gallery not working

What can I do to get it to work?

Wix Editor, Wix Shared Gallery

What are you trying to achieve:
I tested out the Shared Gallery app from Wix on a different website (just to figure out what the features are) but it does not seem to properly work on my customers website. I cannot access it from the editor not apply any changes to it since it just gives me an unknown technical issue. I also cannot remove or add any new Albums.

What have you already tried:
I tried deleting the app from the website altogether but the data that was in it before is still in there. The weird thing is that when I try to access the link: (https://www.christahuber.at/kundengalerie) it seems to work completely fine.