bug at arcade basic?

I’m using Arcade Basic for a couple of years now and think it’s a great free theme. But today I’m getting insane. There seems to be a bug. When I change one url link at a thumbnail, the url link of another y=thumbnail changes too. When I try to correct it, it changes the first url link of the thumbnail.

At the bottom of the page mentioned above there are thumbnails. When you click on ‘LJG’ you are directed to the same page as when you click on ‘Coffee & Cacao’. That’s obviously not what I want. But when I change one of these the other one changes too.

I change the url link and save the changes (also at the mainpage) . It saves the changes but as I said it changes the settings of other thumbnails too.

I really hope someone can help me out. Oh I’m using Mac Os Majove 10.14.
Is that the problem maybe?

Thanks!
Femke

The page I need help with: [log in to see the link]