The current version of GriefPrevention is not able to block trust inheritance from parent claim in subdivisions. Some players recommended `/untrust playername` or `/untrust all` inside de subdivision, but it simply doesn't work. Some versions/forks of the plugin (also for Sponge not Bukkit) have the command /inherit. It should be nice to look at this issue. I can help you if this will be app..
See more