Head on over to your settings, click manage permissions and depending on the type of page you have you’ll see the option to change this.
You should keep in mind however that disabling guest posts also disables what guests see and makes your page appear less interactive and more of a wall. Why do i have to “LIKE” to comment? What if I have an issue with your brand… are you saying I have to be a fan to complain? For every marketing decision think about the impact.
I have exactly the same problem! I can’t put permissions so that only registered users to comment.
How exactly did you do this? Because I’m searching this in Google, found this topic and there is NO explanation on how you did it, which is quite frustrating! Did you change your Facebook page category? Into what?
I only found this which is irrelevant:
“Everyone can post to x timeline
Everyone can add photos and videos to x timeline”