I settled nearby a lake, in a forest area.
Placed a lot of loot on the floor, a tent, dozens of bags filled with tools, weapons, medicine, fishing gear...
Took my car, left for an hour IRL, came back , half the things have vanished. Only the really basic stuff (hacksaw, trowels, logs) remains.

It wasn't in a Safehouse (didn't claim any). Nobody was around when i came back with my car.
Is there a way to know if it was stolen or it it's just a bug ?