IRobot roomba i7+ Failed

I have Connect my roomba i7+ but after a few days it goes online. App Said : device is stopped.

I can only reconnect by deleting and adding device again. Anyone an idea?

Contact the developer of the app

Tryed this Version of the App: iRobot Beta? Have no Problems with the Beta and a i7+ and M6. Also my two devices have an fixed Ip-Adress.