Background:
The initial firmware on these modems was buggy and caused the modem to become unresponsive after running for ~2 days and the only way to fix it was by doing a hard-restart and the cycle continued.
I've been in touch with the relevant people on this issue and they've sent me a new firmware few days back, so far my modem has been up for ~3 days (most up-time since I've gotten it) and everything's going smoothly. It seems the problem has been rectified in this firmware.
Here's a download link for the new firmware:
https://goo.gl/NwWftJ
I would suggest that you factory reset the modem after upgrading the firmware and re-configure the modem so the chance of old configuration messing up things is minimized. Do share feedback and any other problems you encounter (preferably with reproducible steps).