Hi all!.. I had the same issue on both Firefox and Chrome. I am using Visual Studio to edit my configuration files, and noticed that syntax highlighting was not properly functioning too. I had some items with their name not starting with capital letter. I tried changing this and Visual Studio syntax highlighting started functioning properly. Files were correct even before, and things were working well, apart live update on browsers. But after I changed item names and correct formatting of code (at least according to Visual Studio rules) live update in browsers began to work.
Every time that i change something in items and don’t use “correct formatting” live update stops working. It can be even a space or a tab character, that even if does not mean an error in item or sitemap definition code, it make live update in browser stop working.
Hope this can help someone, dig this out.