RAK7249 is not Connecting to N/W Server over LTE Sim

We have Bought RAK7249 Edge Max Gateway, TTN Network Server was enabled and we could see the data Pushing to TTN over WiFi and Ethernet, Intially it was Connected Over LTE and the GW Ran for a Good Amount of time and able to Push the data to N/W Server, but it was unable to connect to the TTN from some time over LTE and unable to see the Data in the TTN.

Any Solutions, to Counter this Issue.