I had this same experience last world - knocked out and robbed while foraging/played around not giving it another thought/three days later suddenly my claim "belongs to someone" (not me!)
Didn't know this was a thing - learned that lesson the hard way! I lost everything - a lot of good stuff.
It had a happy ending, though. About a month later...
The guy who robbed me had stopped playing - another player near me knew the guy and talked to him - the guy logged back on just to give me back my claims!
I've had more decent experience with other players than bad in this game

Just thought I'd throw this in
"He doesn't understand. Explain as you would a child." General Roth'h'ar Sarris