Ok, I found the issue:
the Foo extension uses 2.0.0 version of owl carousel plugin.
So the new syntax is:
responsiveClass:true,
responsive:{
0:{
items:1,
nav:true
},
600:{
items:3,
nav:false
},
1000:{
items:5,
nav:true,
loop:false
}
}
Here’s the link:
https://www.owlcarousel.owlgraphic.com/demos/responsive.html
Would be great to get this options in the extension panel.
Anyway, thanks for the support.