Replacing Telit Modem with Quectel - - no cellular connection

I recently switched my Telit 910 for a Quectel EG25. I ran the same script in Ubuntu as I did for setting up the Telit. However cellular connection status is unavailable. Do I need a new SIM card with this modem? How do I set it up properly? Also I want to be able to tether the modem cell connection into a GLi.Net router in instances where I don’t have a good wifi connection. It connects for a brief second but disconnects abruptly. Advice?