Phone validation – Belgium

Hi,

When I choose for Belgium at the demo page: https://demo.add-ons.org/demo-international-phone-field/ , I can input a mobile number (478112233) and a zone number (55497312). Works perfects.

But when I install the plugin in my WordPress environment, only the mobile number validate. The zone number gets an error.

Do I something wrong?

Thanks!!

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