Hi @positivit,
Unfortunately we have been unable to reproduce this issue.
With only this plugin installed and activated and the current Divi and WordPress versions (at the time of this writing Divi 4.5.1 and WordPress 5.4.2) the Content Visibility input field shows up under Advanced -> Visibility and works as expected in our own tests.
If you could please disable all plugins except Content Visibility for Divi Builder, clear your browser and site caches, and then see if it works, that would be helpful. If it does, locating the problematic plugin by turning the deactivated ones back on one by one would be SUPER helpful! 🙂
I unistalled and re-installed and it works fine.
Thanks for your support.