I don't know that it's bug or my mistake anywhere but I have lot of issues with your upfront builder
1. I used upfront but the main page does not show in sitemap.xml. Is it not necessary to show the front page in XML or I am making any mistake.
2. When I want to use lightbox or floating region, it builds in builder but not built on front side upfront and also not shows on the website. Nothing happens.
3. Sometimes Even after the refreshing cache of upfront and browser, no changes reflect.
4. When I want to download the theme then an error message is "Oops, something seems to have gone wrong."
5. Make a change in the responsive mode for the mobile theme but also reflect in desktop theme. i.e. Font size change.
and many other things.