CloudKit's public container can be accessed on wifi, but not on the cellular network

I'm attempting to write to the public container of CloudKit, but I keep getting the error message:

CKError 0x281ff9ec0: "Network Unavailable" (3/NSURLErrorDomain:-1009); "The Internet connection appears to be offline."

only when I'm accessing the container through the cellular network. When I try on a wifi network, however, it works perfectly fine and can confirm the presence of the uploaded data on the dashboard. There is absolutely nothing wrong with the cellular connectivity of my device.

Code Block swift
let publicCloudDatabase = CKContainer.default().publicCloudDatabase
let operation = CKModifyRecordsOperation(recordsToSave: [exampleRecord], recordIDsToDelete: nil)
let operationConfiguration = CKOperation.Configuration()
operationConfiguration.allowsCellularAccess = true
operationConfiguration.qualityOfService = .userInitiated
operation.configuration = operationConfiguration
operation.perRecordProgressBlock = {(record, progress) in
    print(progress)
}
operation.perRecordCompletionBlock = {(record, error) in
    print("Upload complete")
}
publicCloudDatabase.add(operation)
publicCloudDatabase.save(exampleRecord) { [unowned self] record, error in
    if let error = error {
        print("public cloud database error: \(error)")
    } else {
        print("Sucessfully uploaded to Public Cloud DB")
    }
}

I've tried the different quality of service, like userInteractive, but still doesn't work.

I initialize the container in AppDelegate.swift with the standard code:

Code Block swift
lazy var persistentCloudKitContainer: NSPersistentCloudKitContainer = {
  let container = NSPersistentCloudKitContainer(name: "Example")
   
  guard let description = container.persistentStoreDescriptions.first else {
    fatalError("Could not retrieve a pesistent store description")
  }
   
  let options = NSPersistentCloudKitContainerOptions(containerIdentifier: "iCloud.com.noName.Example")
  description.cloudKitContainerOptions = options
  do {
    try container.initializeCloudKitSchema()
  } catch {
    print("Initialize error: \(error)")
  }
   
  container.loadPersistentStores(completionHandler: { (storeDescription, error) in
    if let error = error as NSError? {
      fatalError("Unresolved error \(error), \(error.userInfo)")
    }
  })
  return container
}()

The Security Role on the dashboard shows that the creator can both read and write.

Xcode: Version 12.0 beta 6
iOS: 14.0