Sleepers are automatically killed after 20 minutes inside a safe zone (Bandit Camp, Barn, Fishing Village, and Outpost). This is an intended part of the game itself -- not a server modification. If you log out in a safe zone, you have to reconnect within that timeframe to move out of there. If you log out in a loot room, you are automatically killed when the loot respawns. The only safe place to log out is inside your own secured base!