At first sight i was sure that it had something to do with appium.
After opening the issue on their repository, i have investigated and confirmed that the unlock functionality of iOS UIAutomator is broken.
I have contacted Apple about this issue, hopefully we won't be retired before they fix it :(
So beware if you have test cases that locks the screen it will not be able to unlock it again and i tried to do it manually by implementing a simple swipe but it seems the program goes in to a state that you cannot inject functions.
That's all for now folks ! :)