Why is my Lumia 1520 having problems recently?

[Windows Central Question]

Phone does not lock. When the screen times out, I cannot unlock the phone anymore. I have to restart the phone. I tried soft reset, but the problem still persists.

I reset my phone to factory settings and updated the software, but Cortana, quiet hours, and other apps are not anymore available. I changed my region, language, and speech settings to US (I'm from the Philippines), restarted my phone, and problem still persists.

I've had this phone for almost 2 years now. I'm not planning to change this year so I want to take better care of my phone. So I'm in need of answers on fixing this problem.

 

[Captain_Eric]

For starters, what build are you on, .107 or 8.1 or other?

FWIW, .107 is working seamlessly on my 1520.3

 

[Juan Santiago Marcos]

Hi. I was the one who asked this question. What do you mean build? My model is 1520.1

 

[Captain_Eric]

Hi. I was the one who asked this question. What do you mean build? My model is 1520.1

For "build" I was referring to Windows 10 Mobile Insider Preview, ie the operating system. By .107, I meant build 10586.107 and by 8.1 I meant Windows Phone 8.1.

Hardware is another matter, which I gather you understand. Mine is a 1520.3, which officially is a RM-938.