call and data connectivity issues with one plus 6T via OnePlus 6T

  1. X1559984215293
    Cupcake Oct 24, 2019

    X1559984215293 , via OnePlus 6T , Oct 24, 2019 :
    I am facing all the issues such as
    1. calls doesn't hang up even after disconnecting call.
    2. there is missed call alert when phone has not even range up.
    3. sometime I have to call two three times, only after that called get connected.
    4. call drops.

    Pls help me to know any solution to these.