Samsung A7 2018

[1234522]

I am using airtel sim and Whenever I recharge my mobile phone, Issue is coming after recharge, one 
Notification (sign in to network airtel ) in the notification panel comes whenever I switch ON my mobile data. When I click on this notification  it says webpage not available..

Any idea why it is coming..and any solution..

[anaf]

your sim is disconnected. contact airtel customer service