I have a small core data library. I use contexts this way: public private(set) lazy var masterContext: ManagedObjectContext = { [weak self] in         let context = ManagedObjectContext(concurrencyType: .privateQueueConcurrencyType)         context.persistentStoreCoordinator = self?.persistentStoreCoordinator         context.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy         return context     }()     public lazy var viewContext: ManagedObjectContext = { [weak self] in         let context = ManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)         context.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy         context.parent = self?.masterContext         return context     }()     public var newTemporaryContext: ManagedObjectContext {         let context = ManagedObjectContext(concurrencyType: .privateQueueConcurrencyType)         context.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy         context.parent = viewContext         return context     } I usually create a temporary context to insert new data, once it's done, I get that data using the viewContext These are my tests: override func setUp() {         super.setUp()         let bundle = Bundle(for: FilterTests.self)         kangaroo = KangarooStore(name: "TestDB", storageType: .memory, bundle: bundle)         kangaroo.loadStoreSync()         kangaroo.saveSync(in: .view, block: { context in             let entity2 = TestEntity(in: context)             entity2.id = 2             entity2.name = "entity2"             entity2.lastname = "test"             let entity1 = TestEntity(in: context)             entity1.id = 1             entity1.name = "entity1"             entity1.lastname = "test"             let entity5 = TestEntity(in: context)             entity5.id = 5             entity5.name = "entity5"             entity5.lastname = "test"             let entity6 = TestEntity(in: context)             entity6.id = 6             entity6.name = "entity6"             entity6.lastname = "test"         })     } func testFilterInViewContext() {         do {             let predicate = NSPredicate(format: "id = %@", 1 as NSNumber)             let query = Query<TestEntity>(in: kangaroo.viewContext).filtered(using: predicate)             let entities = query.execute()             XCTAssertEqual(entities.count, 1)             XCTAssertEqual(entities[0].id, 1)             XCTAssertEqual(entities[0].name, "entity1")         }     } on iOS 13.6 and backwards, "testFilterInViewContext" runs fine, but in iOS 14 beta 6 it fails. What could be happening? Thanks in advance!