No NSEntityDescriptions in any model claim the NSManagedObject subclass 'CoreDataExampleTests.TodoMO' so +entity is confused

I have a DataManager class as follows:

enum DataManagerType {
    case normal, preview, testing
}

class DataManager: NSObject, ObservableObject {

    static let shared = DataManager(type: .normal)
    static let preview = DataManager(type: .preview)
    static let testing = DataManager(type: .testing)

    @Published var todos = [Todo]()

    fileprivate var managedObjectContext: NSManagedObjectContext
    private let todosFRC: NSFetchedResultsController<TodoMO>

    private init(type: DataManagerType) {
        switch type {
        case .normal:
            let persistentStore = PersistentStore()
            self.managedObjectContext = persistentStore.context
        case .preview:
            let persistentStore = PersistentStore(inMemory: true)
            self.managedObjectContext = persistentStore.context
            for i in 0..<10 {
                let newTodo = TodoMO(context: managedObjectContext)
                newTodo.title = "Todo \(i)"
                newTodo.isComplete = false
                newTodo.date = Date()
                newTodo.id = UUID()
            }
            try? self.managedObjectContext.save()
        case .testing:
            let persistentStore = PersistentStore(inMemory: true)
            self.managedObjectContext = persistentStore.context
        }

        let todoFR: NSFetchRequest<TodoMO> = TodoMO.fetchRequest()
        todoFR.sortDescriptors = [NSSortDescriptor(key: "date", ascending: false)]
        todosFRC = NSFetchedResultsController(fetchRequest: todoFR,
                                              managedObjectContext: managedObjectContext,
                                              sectionNameKeyPath: nil,
                                              cacheName: nil)
        super.init()

        // Initial fetch to populate todos array
        todosFRC.delegate = self
        try? todosFRC.performFetch()
        if let newTodos = todosFRC.fetchedObjects {
            self.todos = newTodos.map({todo(from: $0)})
        }
    }

    func saveData() {
        if managedObjectContext.hasChanges {
            do {
                try managedObjectContext.save()
            } catch let error as NSError {
                NSLog("Unresolved error saving context: \(error), \(error.userInfo)")
            }
        }
    }

    private func fetchFirst<T: NSManagedObject>(_ objectType: T.Type, predicate: NSPredicate?) -> Result<T?, Error> {
        let request = objectType.fetchRequest()
        request.predicate = predicate
        request.fetchLimit = 1
        do {
            let result = try managedObjectContext.fetch(request) as? [T]
            return .success(result?.first)
        } catch {
            return .failure(error)
        }
    }
}

My persistence store is as such:

struct PersistentStore {

    let container: NSPersistentContainer

    init(inMemory: Bool = false) {
        container = NSPersistentContainer(name: "CoreDataModel")
        if inMemory {
            container.persistentStoreDescriptions.first!.url = URL(fileURLWithPath: "/dev/null")
        }
        container.viewContext.automaticallyMergesChangesFromParent = true
        container.loadPersistentStores(completionHandler: { (storeDescription, error) in
            if let error = error as NSError? {
                fatalError("Unresolved error \(error), \(error.userInfo)")
            }
        })
    }

    var context: NSManagedObjectContext { container.viewContext }

    func saveContext () {
        if context.hasChanges {
            do {
                try context.save()
            } catch let error as NSError {
                NSLog("Unresolved error saving context: \(error), \(error.userInfo)")
            }
        }
    }
}

I get an error when calling:

let predicate = NSPredicate(format: "id = %@", todo.id as CVarArg) //todo.id is just some UUID() //irrelevant here
let result = fetchFirst(TodoMO.self, predicate: predicate)

This is the error:

2022-07-09 21:36:17.425709-0400 CoreDataExample[73965:7495035] [error] error: No NSEntityDescriptions in any model claim the NSManagedObject subclass 'CoreDataExampleTests.TodoMO' so +entity is confused. Have you loaded your NSManagedObjectModel yet ? CoreData: error: No NSEntityDescriptions in any model claim the NSManagedObject subclass 'CoreDataExampleTests.TodoMO' so +entity is confused. Have you loaded your NSManagedObjectModel yet ? 2022-07-09 21:36:17.425780-0400 CoreDataExample[73965:7495035] [error] error: +[CoreDataExampleTests.TodoMO entity] Failed to find a unique match for an NSEntityDescription to a managed object subclass CoreData: error: +[CoreDataExampleTests.TodoMO entity] Failed to find a unique match for an NSEntityDescription to a managed object subclass /Users/santiagogarciasantos/Documents/Xcode Projects/CoreDataExample/CoreDataExample/DataManager/DataManager.swift:87: error: -[CoreDataExampleTests.CoreDataExampleTests test_Add_Todo] : executeFetchRequest:error: A fetch request must have an entity. (NSInvalidArgumentException)

I've checked the target, made sure my Entity is in "Current Product Module" but it still won't work.

Important: This only occurs when I'm testing (using my DataManager.testing)