Have you needed to reboot every day since you got it, or is this something that only started in the last few months?
I'm not sure why loosing connection daily would be a router issue. More likely a connection issue.
You can check coverage and network status at Check mobile coverage where you can also report any issues you are facing, as well as sign up for updates on any known issues that may be going on.
It may also be worth contacting the technical team one more time where the team could perform a SIM refresh to ensure connection is stable.
