Imported users are not able to login
Ultimate Member does not have the import functionality, so you must use other plugins to import users into a WordPress site. You can learn more here.
You might find a conflict with the following plugin: Import and export users and customers. The common problem encountered is that imported users are not able to log in because of too many redirects errors the reason why is because the force password reset doesn’t work with customised login systems such as Ultimate Member, so you need to unset this flag.
To unset the flag and solve the issue, you need to run the following SQL statement:
<?php global $wpdb; $wpdb->query(“DELETE FROM wp_usermeta where wp_usermeta.meta_key=’acui_force_reset_password’ “); ?>
Note: You need to run the code once or twice and test until the issue is resolved.