We're sorry to hear if you are having issues with our product. The FLIP 3, as well as the rest of our portable speakers, has a power-saving feature wherein it will automatically enter the Standby mode after it detects no audio signal for 10 minutes. Upon detecting an audio signal, the system will turn on and play audio. So if you have the volume on the FLIP 3 cranked up, and the volume on your source device is set really low, it is most likely that the FLIP 3 is not getting enough audio signal for it to stay on. Please try turning the volume down a bit on the FLIP 3, and then crank up the volume on your source device to get to the level you desire. This will send a continuous audio signal to the FLIP 3 and it should stay on without any issues.
If the issue still persists after trying this, please submit a case at www.jbl.com/support-contact.html and our Customer Service team will be glad to assist you.