I have a Wordpress installation with a modified TwentySeventeen theme. When on any page of the admin I can click the "Screen options" tab and it expands but it is completely empty.
Nothing in my theme is disabling this feature as far as I can find. If I read the Wordpress manual pages correctly, it should be enabled by default.
Anyone have any ideas?
Ok, found it. Not really Wordpress related but might be helpful to someone anyway.
It was my browser ad blocker plugin. Apparently it adds CSS to pages upon loading. The CSS showed as "inline" in the dev tools inspector but didn't show at all when viewing page source code. When checking the CSS of the admin page, I found a lot of things being hidden, amongst which this selector: [id^="adv-"] which applied to the screen options. A lot of other selectors had "AD", "Google" and "Twitter" in their names. I did not have any plugin that would add these things but finally figured out it might be the ad blocker, which turned out to be correct.
social- and AdBlock Plus. Glad you found it this quick