Screen won't lock!

[blade4life1889]

This is driving me mad!
i used to be able to press the (right hand) power button to lock the screen. For some reason it's just not working now.
I've been through all the processes I can find (powering off and on etc.) but nothing works.
Also, I have my phone set to lock after 15 seconds of inactivity - that's not working either.
All this means the phone is 'open' all the time. I can't even have it in my pocket.
PLEASE HELP!!

 

[B. Diddy]

Welcome to Android Central! "Lock instantly with Power key" is toggled on? www.samsung.com/ca/support/mobile-d...i-set-a-screen-lock-for-my-samsung-galaxy-s9/

 

[krisqz]

Sounds like some rogue app. Try to boot in safe mode.