Problem is with result of wp_logout_url();
When plugin is active its generate wrong url, like this:
/wp-login.php?_wpnonce=50efde7c4c
When plugin is not active, its generate URL which works:
/wp-login.php?action=logout&redirect_to=index.php&_wpnonce=43a289b322
If i active plugin, and use second URL, it will log me out.