SwiftData - 3 Models referencing each other not possible?

Hi fellow Swifties,

Been pulling my hair out for 8+ hours and need your help :( Tried creating 3 models that are cloudkit compatible, but the app crashes every time I try to add an Object to the modelContext.

Error: Thread 1: EXC_BREAKPOINT (code=1, subcode=0x18ec49d2c)

My guess: I think it is trying to force unwrap a nil...

Can do: Insert Item() and Location() into modelContext + syncronizing to cloudkit without any errors.

modelContext.insert(Item())
modelContext.insert(Location())

Can not do: Insert Object() into modelContext.

modelContext.insert(Object())

Am I not initialising them correctly? Is this approach bad? Or am I experiencing a bug?

Help is much appreciated <3

My 3 models:

@Model
class Item: Identifiable {
    var id: UUID = UUID.init()
    var name: String = String()
    var barcode: String = String()
    @Relationship(deleteRule: .cascade, inverse: \Object.item)
    var objects: [Object]?
    @Attribute(.externalStorage)
    var photo: Data?
    
    init(name: String = String(), barcode: String = String(), photo: Data? = nil) {
        self.name = name
        self.barcode = barcode
        self.photo = photo
    }
}
 
@Model
class Location: Identifiable {
    var id: UUID = UUID.init()
    var name: String = String()
    @Relationship(deleteRule: .cascade, inverse: \Object.location)
    var objects: [Object]?
    var isFavorite: Bool = Bool(false)
    
    var unwrappedObjects: [Object] {
        objects ?? []
    }
    
    init(name: String = String(), isFavorite: Bool = Bool(false)) {
        self.name = name
        self.isFavorite = isFavorite
    }
}
 
@Model
class Object: Identifiable {
    var id: UUID = UUID.init()
    var amount: Int = Int()
    var expiryDate: Date? = nil
    var location: Location?
    var item: Item?
    
    init(amount: Int = Int(), expiryDate: Date? = nil) {
        self.amount = amount
        self.expiryDate = expiryDate
    }
}