Possible cause 3 of 3:
No 4G connection established
The modem application automatically establishes a 4G connection to the internet if 4G has been turned on in the modem application and if you have 4G network coverage.
What you need to do
Check if the modem application has established a 4G connection. If you don't have a 4G connection, make sure that the modem application is set to search for both 2G, 3G and 4G networks.
If you're still not able to establish a 4G connection to the internet, you don't have 4G coverage.
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