I had stored an Ada and a Sarka inside the double-entrance shed model that has the two elevated platforms on each side with the hay mounds.
The Ada was parked under one of the stairs, while the Sarka was on the middle of the shed.
Upon rejoining hours later, the Sarka had been moved outside while the Ada was gone.
I made sure the based had not been raided nor entered. The gates where code-locked and reinforced. No signs of forced entry.
Additionally, an unfinished wall within the shed was relocated outside on the street. This would indicated that it was, in fact, some bug, and not another player raiding the base.
This is a report.