Hi,
Do you have any other plugin installed for login related features ?
Yes, other plugin is Ultimate Member.
Detail log error like this:
WordPress database error Column ‘username’ cannot be null for query INSERT INTO wp_loginizer_logs (username, time, count, ip, lockout, url) VALUES (NULL, 1611232563, 1, ‘(…sorry,hidden by me..)’, 0, ‘(…sorry,hidden by me..)’) made by require(‘wp-blog-header.php’), require_once(‘wp-includes/template-loader.php’), do_action(‘template_redirect’), WP_Hook->do_action, WP_Hook->apply_filters, um\core\Form->form_init, do_action(‘um_submit_form_errors_hook’), WP_Hook->do_action, WP_Hook->apply_filters, um_submit_form_errors_hook, do_action(‘um_submit_form_errors_hook_login’), WP_Hook->do_action, WP_Hook->apply_filters, um_submit_form_errors_hook_login, do_action(‘wp_login_failed’), WP_Hook->do_action, WP_Hook->apply_filters, loginizer_login_failed
