Sometimes lock screen keypad not shown

[pakmul]

A few times the keypad to enter pin to unlock the phone does not appear. Therefore, there is no way to enter the pin to unlock it. I am not sure when/how it happens, I noticed that I have been happening in previous build also.
I practically have to restart the phone by pressing/holding on the power button.

Any ideas ?

Lumia 950XL Build 14393.351

Thanks!

 

[abhishek singh21]

perform a soft reset by holding volume down+power key until phone reboots , additionally remove the pin from lock screen and add it back again then check if this issue still remains.