There has been a bug since the rust update.
Since the last wipe, saving turret positions for cars no longer works correctly (using the "Car Turrets" plugin).Furthermore, there are problems saving positions for string lights, elevators, and caravan modules.

(17:37:44) | Concave Mesh Colliders are not supported when used with dynamic Rigidbody GameObjects.

Either make the Mesh Collider convex, or make the Rigidbody kinematic. Scene hierarchy path "assets/content/vehicles/modularcar/4module_car_spawned.entity.prefab/assets/content/vehicles/modularcar/module_entities/1module_cockpit_armored.prefab/assets/prefabs/npc/autoturret/autoturret_deployed.prefab/sentry", Mesh name "sentry.base_COL"

(17:37:44) | Concave Mesh Colliders are not supported when used with dynamic Rigidbody GameObjects.

Either make the Mesh Collider convex, or make the Rigidbody kinematic. Scene hierarchy path "assets/content/vehicles/modularcar/4module_car_spawned.entity.prefab/assets/content/vehicles/modularcar/module_entities/2module_camper.prefab/assets/prefabs/npc/autoturret/autoturret_deployed.prefab/sentry", Mesh name "sentry.base_COL"                                                                                                                                                                        

                    ( car turrets )