The Mobility on Board alarm clock, model CO-BL-02, can also function without a connection to a mobile phone. It has its own clock and alarm function that works independently of a Bluetooth connection.

If the alarm only goes off sporadically, it could be due to an incorrect setting or a problem with the battery or the device itself. It would be advisable to check the instructions again and make sure that the alarm times have been entered correctly. If the problem persists, it may be helpful to restart the device or contact the manufacturer.