I am having the exact same issue. With ultimate members installed it removes all options standard WordPress user options like delete etc and replaced it with “remove” which does nothing but removes it from the the WordPress dashboard users page. All intomation is still in the database. The entry remains in the wp_users table and all of the meta data in the wp_usermeta table.
I manually deleted the information from the database which allowed me to register with the same email address again for testing purposes. I currently have 2 users registered on my website. The users page shows 2, the wp_users table shows 2, the metadata table shows 2 however when I click the ultimate members dashboard it says I have 6 inactive accounts and 2 active. Where is the options to actually delete a user and its data from the website without having to remove information from the database manually?
