Lock screen not locking

[imex99]

After waking my phone, the lock screen isn't coming up. I've tried setting the pattern and passcode but stops working after a bit. Any reason for this?

Sent from my LS670 using Tapatalk

 

[RUSH]

There isn't a definate solution for that kind of issue. Try some troubleshooting. (i.e. rebooting, or restarting the device.