Links in WPBakery Page Builder Models not working

Hi, Im using WPBakery Page Builder for modals in my site. i have many sub domains and i wanted to put a link in one modal in my main domain as a pop up of a document which is in one of the sub domain. the link is working fine while opening in seperate browser or in a page but its not working while i keep in modals. There is a message showing “www.subdomainname has refused to connect” in the front page. please help me?