My screen options under “post” won’t work. I have checked them all off but nothing shows up. I have done a full update twice now and that did not solve the problem. I also deactivated all the plug ins and that didn’t work either.
Do you have the WP Security Scan plugin enabled? If so, disable it and see if it works. You can always re-enable WP Security Scan (a fabulous plugin) when you need it again later. I enable it every few weeks to make sure my settings are still secure on client sites.