I entered quite a few "Advanced Blocking" ranges two days ago.
Today I logged in and discovered that all of them disappeared: the "Current list of ranges and patterns you've blocked" on the "Advanced Blocking" page is empty.
How could it happen?
I am the only "administrator" role user.
WP, all plugins and themes are up-to-date.
Wordfence never reported any suspicious activity.
I did get a handful spam user registrations in the last week, all by default are in "subscriber" role.