If your ‘Blu Grand X LTE’ device is failing to connect to a local network, this would usually indicate that the phone is being used in a location with limited network coverage / poor signal strength.
To test this, please try performing a network search to select a network manually –
1) Go to the ‘Apps’ screen (apps icon is a white circular button with 6 dots inside at the bottom of the ‘Home’ screen)
2) Select “Settings” (icon shows a picture of a gear / cog wheel).
3) Select “More”.
4) Select “Cellular Networks”.
5) Select “Network Operators”.
6) Select “Search Networks” and wait while the search completes.
7) Try manually selecting any of the networks shown and retest the service.
8) If this resolves the issue, please change the network search mode back to “Choose Automatically” when you move to a new location.