Good morning, a strange problem appeared a few days ago on the Ultra S 24, a strange chirp sounds - as if some kind of message or notification without any marking for the application is not the usual sound of notifications on the device. Appeared suddenly, nothing new was installed, the beep sounds randomly whenever it wants, can appear 5 times an hour and then not appear for a few hours and again whenever it wants once or twice etc. Does anyone have an idea what this is due to? If I lower the volume of the media ringtone Totally then the sound doesn't appear. NFC+Bluetooth is off. I would appreciate advice . thanks doron