try re-adding bz

ads_and_trackers1.txt

@@ -3562,6 +3562,7 @@ www8.glam.com
 www-banner.chat.ru
 www.dnps.com
 www.facebook.com/tr/
+www.facebook.com/ajax/bz
 www.google-analytics.com
 www-google-analytics.l.google.com
 www.googletagservices.com