Try the following solutions:
1.Check that your SIM card supports LTE or WCDMA.
2.Check that your SIM card is in your ISP’s service area.
3.Check that your SIM card balance is sufficient.
4.Start a web browser on the device connected to the router, and access //tendawifi.com. You will be redirected to the troubleshooting page. Then, perform troubleshooting as prompted on the page.
5.Confirm with your ISP if you are in a roaming service area. If yes, log in to the web UI of the router and navigate to Internet Settings to enable Data Roaming.
If the problem persists, contact our technical support.
UG - 3,4,5,8A and 11, Devika Tower,Nehru Place, New Delhi, India - 110019