I cannot: Turn off screen lock.

As the headline says, I cannot unclick the box, under Security & Privacy settings. When I try it asks for a password, then it says; Are you sure? And have a box saying TURN OFF SCREEN LOCK. After pressing it, it just puts back the little CHECK sign in the box again. HAHAHA!! I can't even change the bar with: "immediately" to any time limit, it just does the exact same thing, and goes back to: "immediately".

I have an MacMini 2012 and after a clean install of Mountain lion - upgrade to High Sierra, I cannot uncheck the box, I've now upgraded to Mojave and still have the same problem.

I've restarted the Mac multiple times, I've reset the PRAM, SRAM JDOIDSAOI OWAIJDNLAEJWNr... Nothing works.

Please way in if you have another solution 😀