A Mangoh Red using WP77 Octave FW 3.5.2 suddenly began rebooting frequently (20-30 times in 24 hours) and was unable to sync with Octave UI for extended periods of time. Finally after re-installing FW the device stabilized. IT appears that when the device can access LTE, it is stable. For some reason it sometimes gets stuck on GSM And the connectivity issues ensues. The test device is stationary and at the same location other devices have no problems. This device is using a Sierra SIM. Are there known issues with the Sierra SIM network selection? This is causing a good deal of lost time. Please recommend a solution. Could the internal SIM perhaps be used and perhaps be changed to AT&T?