ShreyasPatil_ , via OnePlus 8T , Jan 19, 2021 : Try resetting network settings. Also check if volte is available.
Ronit9271 , via OnePlus Nord , Jan 19, 2021 : Do Airplane mode 2 ,3 times then check.Then also issue then restart the phone.
A.Saketh Gupta , via OnePlus 8T Aquamarine Green , Jan 20, 2021 : Thats based on your service provider and Open my Jio app and trouble shoot your network if any problem occurs troubleshoot your sim and raise a complaint on my jio app
Shiva8267 , via OnePlus Community App , Jan 20, 2021 : Looks like carrier issue contact service center
