Please check this issue. I’ve noticed this since 2.0 Beta, but I didn’t record it.
When I edit css code in tablet breakpoint, it will update and overwrite the custom css code in desktop. It doesn’t happen always. I am not quite sure about its happening pattern
We’ve fixed this issue in Bricks 2.0, now available as a one-click update in your WordPress Dashboard.
Please take your time to read the changelog entry before updating: Bricks 2.0 Changelog – Bricks, and let us know if you continue to experience issues.