Dispatch queue: com.apple.NSURLSession-delegate after executing self written shortcut

Currently I am trying to create some shortcuts for my iOS 17 app. The AppIntent looks like this:

class PostClass{
    
    public init() {

        let url = URL(string: "http://myurl")!
        var request = URLRequest(url: url)
        request.httpMethod = "POST"
        struct Message: Encodable {
            let device_type: String
        }
        let message = Message(
            device_type: "device"
        )
        let data = try! JSONEncoder().encode(message)
        request.httpBody = data
        request.setValue(
            "application/json",
            forHTTPHeaderField: "Content-Type"
        )
        self.request = request
    }
}

var activateDevice = PostClass()

@available(iOS 17, *)
struct ActivateIntent: AppIntent {
  static let title: LocalizedStringResource = "Activate"

  func perform() async throws -> some IntentResult {
      
      let task = URLSession.shared.dataTask(with: activateDevice.request) { data, response, error in
          let statusCode = (response as! HTTPURLResponse).statusCode
          
          if statusCode == 200 {
              print("SUCCESS")
          } else {
              print("FAILURE")
          }
      }
      task.resume()
    return .result()
  }
}

Unfortunately, the shortcut throws an error after every second execution. I looked into the ips-file and saw the following traceback:

Thread 2 Crashed:
0   Runner                        	       0x1028ddd30 closure #1 in ActivateIntent.perform() + 388
1   CFNetwork                     	       0x1a6f39248 0x1a6f2a000 + 62024
2   CFNetwork                     	       0x1a6f57210 0x1a6f2a000 + 184848
3   libdispatch.dylib             	       0x1adced13c _dispatch_call_block_and_release + 32
4   libdispatch.dylib             	       0x1adceedd4 _dispatch_client_callout + 20
5   libdispatch.dylib             	       0x1adcf6400 _dispatch_lane_serial_drain + 748
6   libdispatch.dylib             	       0x1adcf6f64 _dispatch_lane_invoke + 432
7   libdispatch.dylib             	       0x1add01cb4 _dispatch_root_queue_drain_deferred_wlh + 288
8   libdispatch.dylib             	       0x1add01528 _dispatch_workloop_worker_thread + 404
9   libsystem_pthread.dylib       	       0x201dd4f20 _pthread_wqthread + 288
10  libsystem_pthread.dylib       	       0x201dd4fc0 start_wqthread + 8

Is there any way to locate the error with these information? Has it something to do with the fact that my code is not thread-safe? Or is there any internal bug?

Grateful for any help, thanks in advance!