Iphone 6 statusbar spinner bar is continuously spinning

i have iphone 6 ios 11.3 from two days i notice that status bar in iphone always keeps spinner spinning. when i on wifi or cellular data i m really feels that iphone is stuck on some where i don't know why but this activity is drains my battery so heavily, i tried restarting phone even i restart many times when i switch on cellular data or wifi this spinner comes again and when i off wifi and cellular data this spinner goes off so quickly, what happening in phone 😟