The improvements we've made to the Buildxact experience are designed to increase the simplicity and ease of use of the platform.
This first release has been designed for desktop use, so currently the mobile experience will remain as it is.
This means if you access Buildxact on your phone or some tablets (depending on screen resolution) and have the new experience preview turned on, it will automatically switch you back to the original navigation model.
You can toggle back and forward using the orange bar shown at the top of the image above, we reccomend you leave the bar there if you ever need it. If you do close the orange bar and need it again, simply log out and in, it'll be there again.
Stay tuned for the new experience for mobile devices.