To replicate it, you will need to have 6-7 global classes there (in case you didn’t do that much). Then, do the drag/drop the way I did in the screencast. As you see the screencast, you will see the first global class was affected even if I just drag a little or drag to the middle of them.
We’ve addressed this in Bricks 2.4-beta (beta release), now available for manual download from your Bricks account.
Please read the changelog entry before testing, and let us know if you experience any issues. Note: beta builds are not recommended for production sites.