Upfront blog changes not working

1) Changes made in Upfront Builder for Blog page not showing in frontend. Trying to customize the /blog page layout, by clicking the "Layouts" button, and going to the singel blog page layout, the changes made are showing in Upfront Builder, but it isn't showing in the frontend when the /blog page is loaded.

2) Getting 404 page every time Upfront Builder is loaded, instead of the homepage.