[iOS] PlatformException on subscribeToCharacteristic | Device connects successfully.

[devtyagi-c]

Describe the bug

(Works fine on Android)

I perform these operations on iOS:

• Connect to Device, move to a new screen
• Click on start monitoring button
• On the click of the button the following operations are performed
  1. Enable notifications on characteristic 86f66001-f706-58a0-95b2-1fb9261e4dc7
  2. Enable notifications on characteristic 86f65002-f706-58a0-95b2-1fb9261e4dc7
  3. Write 0x0213C87462 on characteristic 86f65001-f706-58a0-95b2-1fb9261e4dc7
  4. Write 0x66 on characteristic 86f65001-f706-58a0-95b2-1fb9261e4dc7

And I get this error:

PlatformException (PlatformException(reactive_ble_mobile.Central.(unknown context at $10590a818).Failure:1, The operation couldn’t be completed. (reactive_ble_mobile.Central.(unknown context at $10590a818).Failure error 1.), {}, null))

Is there any fix for this?

To Reproduce
Steps to reproduce the behavior:
Mentioned above ^

Expected behavior
I should not get this exception, it works perfectly fine on Android.

• I tried doing the same with a general BLE scanner application (e.g. nRF Connect) and it exhibits the expected behavior as described above

Smartphone / tablet

• Device: [e.g. iPhone 13]
• OS: iOS 17.5.1
• Package version: ^5.3.1

Peripheral device

• Vendor, model: CUSTOM
• Does it run a custom firmware / software: yes

Additional context

Here is my code:

Here is my code for the start monitoring button:

Future<void> startMonitoring() async {
    if (state.selectedDeviceId == null) {
      emit(state.copyWith(error: "No device selected"));
      return;
    }

    if (state.connectionState != DeviceConnectionState.connected) {
      emit(state.copyWith(error: "Device not connected"));
      return;
    }

    // Emit initial state
    emit(state.copyWith(isSettingUpMonitoring: true, error: null));

    try {
      await Future.delayed(const Duration(seconds: 2));

      // Enable notifications on 6001
      _monitorSubscription6001 = _monitorCharacteristic
          .execute(
        state.selectedDeviceId!,
        "86f66000-f706-58a0-95b2-1fb9261e4dc7",
        "86f66001-f706-58a0-95b2-1fb9261e4dc7",
      )
          .listen(
        (data) {
          // Emit state when a new value is received from 6001
          log("Received data from 6001: $data");
          emit(state.copyWith(characteristicValue: data.toString(), isMonitoring: true, isSettingUpMonitoring: false));
        },
        onError: (error) {
          emit(state.copyWith(error: error.toString(), isMonitoring: false, isSettingUpMonitoring: false));
        },
      );

      await Future.delayed(const Duration(milliseconds: 200));

      // Enable notifications on 5002
      _monitorSubscription5002 = _monitorCharacteristic
          .execute(
        state.selectedDeviceId!,
        "86f65000-f706-58a0-95b2-1fb9261e4dc7",
        "86f65002-f706-58a0-95b2-1fb9261e4dc7",
      )
          .listen(
        (data) {
          // We do not need to emit the state here when a new value is received from 5002
          log("Received data from 5002: $data");
        },
        onError: (error) {
          emit(state.copyWith(error: error.toString(), isMonitoring: false, isSettingUpMonitoring: false));
        },
      );

      await Future.delayed(const Duration(milliseconds: 200));

      await _writeCharacteristic.execute(
        state.selectedDeviceId!,
        "86f65000-f706-58a0-95b2-1fb9261e4dc7",
        "86f65001-f706-58a0-95b2-1fb9261e4dc7",
        [0x02, 0x13, 0xC8, 0x74, 0x62],
      );

      log("Successfully wrote data to 86f65001-f706-58a0-95b2-1fb9261e4dc7");

      await _writeCharacteristic.execute(
        state.selectedDeviceId!,
        "86f65000-f706-58a0-95b2-1fb9261e4dc7",
        "86f65001-f706-58a0-95b2-1fb9261e4dc7",
        [0x66],
      );

      log("Successfully wrote data to 86f65001-f706-58a0-95b2-1fb9261e4dc7");
    } catch (e) {
      // Emit state when an error occurs
      log("Error: $e");
      emit(state.copyWith(
        error: e.toString(),
        isMonitoring: false,
        isSettingUpMonitoring: false,
      ));
    }
  }