2) It will attempt to catch LTE, 4G when you touch the attempt button.
3) During the frequency catching procedure, the mark of LTE or 4G can disappear and appear for catching the LTE or 4G frequency perfectly.
4) Please wait for completing the procedure. If not working well, please try again after turning off the phone and on.
#. sorry, but for some devices, you need to turn the airplane mode on and off manually.