WPML Multilanguage Problem

I have site multilanguage with WPML plugin for language.

On menu I have the flags selector: ITA – ENG

When I’m on italian site: http://www.miosito.it/servizi/ and I click on flag English it is not extenal link and it open on same window.

When I’m on english site: http://www.miosito.it/en/services/ and I click on flag Italian it is opened on external tab.

If I disable external links all flags works perfect.

Thanks