Go to OSX Daily to read How to Disable Missed Call Return from iPhone Lock Screen
Some iPhone users have found the feature which allows you to return a missed phone call from the iPhone Lock Screen can result in unintentionally dialing a number or returning a call when you don’t intend to. This usually happens if someone swipes or taps on the notification of a missed call, which then calls the person back automatically.
If you don’t want the ability to automatically return a missed call from the iPhone lock screen, and you’d rather return calls manually, you can turn off the ability to return missed calls from the iPhone Lock Screen.
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