Can't create a firewall rules

Hi, we are trying to create a WAF rule (pro account) with this rule:

(http.request.uri.path contains "/users/create" and not ip.src.country in {"IT" "SM"})

(http.request.uri.path contains "/users/create" and not ip.src.country in {"IT" "SM"})

But the page does nothing, literally. When I press save as draft or publish, the page does nothing.

Any help ?