Ever since OH2 2.0.0 Stable and up to 2.1.0-Snapshot #858 I have had this little ‘snag’.
Even minor editing in my .items file such as ‘labeltext’ or ‘iconname’ in Eclipse SmartHome Designer renders group-items in my sitemap shuffled when viewed in Basic UI or HabDroid.
Also happens after defining new items.
After a OH2 restart, the proper ordering is restored.
No big deal, but each restart runs the risk of losing a node as I experienced lately. (A Nexa AD-146 was suddenly no longer part of my network. Had to delete its .xml file, reset it and include anew)