Unable to monitor the peripheral

[vikoo]

Hi, I used the below code to monitor the data from the ble.

peripheral
              .monitorCharacteristic(SensorTagTemperatureUuids.myService,
                  SensorTagTemperatureUuids.myCharacteristic)
              .map((characteristic) => characteristic.value),
          log);

This code works fine on android but it's not working on iPhone 6S.
I am getting below Error:

new DeviceDetailsBloc.: Error while monitoring characteristic [ ] BleError (Error code: 403, ATT error code: 10, iOS error code: null, Android error code: null, reason: The attribute could not be found., internal message: null, device ID: 62F110E1-9327-473B-5DF4-AFAE3FE12938, service UUID: 0000ffe7-0000-1000-8000-00805f9b34fb, characteristic UUID: 0000ffe9-0000-1000-8000-00805f9b34fb, descriptor UUID: null)

Characteristic: [ ] uuid: 0000ffe9-0000-1000-8000-00805f9b34fb [ ] isReadable: true [ ] isWritableWithoutResponse: false [ ] isWritableWithResponse: true [ ] isIndicatable: false [ ] isNotifiable: true

Please help me where is it getting wrong?