There can be a number of different reasons for the “Your Device Is Offline” error. The most common reason is our poor internet connection.
Follow the step-by-step instructions to fix this issue,
1. First, you will need to go to Settings.
2. And navigate to “Sim cards & mobile networks” settings.
3. You need to select the Sim network.
4. After that, enter into the Mobile networks.
5. And enable Manual Settings.
6. Now you are registered on a Network.
7. You will need to turn On & Off the Airplane Mode.
8. And then enter into the App Settings.
9. Now you have to enter into Manage apps.
10. And click on Clear Data.
11. After that, finally restart your mobile.