It is very strange.
Scenario: I arrived in my super car to explore the laboratory. Left her outside, of course. I took a cart with me. I cleaned one floor and saved and left the game. When I went back into the game, I found that my cart now belongs not to me, but to the poor from the lobby. Having run outside, I realized that they “stole” the car too.
And so, the question is: how do I get the cart and car back? 
P.S I hope this will be fixed soon, since I don’t play normally. I downloaded the save where everything is in order. But, soon the problem reappeared. Maybe the whole thing is in the laboratory (or in the scientific center (I don’t remember, if it is important, I’ll clarify. ) )