Since elementor and themeedifor-front use frontoffice preview as iframe it must be loaded on correct domain.

for example if you have multistore with two domain

www.shop1.com

www.shop2.com

and your backoffice url is www.shop1.com/admin

to edit shop 1 login to backoffice with  www.shop1.com/admin and in topbar select shop1 shop context and you can edit

if you want to edit shop2 then login to backoffie with www.shop2.com/admin  and in topbar select shop2 shop context and you can edit