FYI: I thought I had the same issue. After trying different settings I’ve found were my problem was…. I am using WP 3.7.1 with Wordfence 3.8.8 and the live traffic log remained empty. Actually my website is still under construction and i am using Ultimate Coming Soon Page plugin v 1.10.0 . When this plugin is active, live traffic is empty, no matter what. When de-activated, Live traffic is working perfectly. The ultimate coming soon page plugin does not change the htaccess file, so I think it is just an incompatibility issues between the two plugins. That’s it, just to let you know. Wordfence & Ultimate Coming Soon Page plugin don’t work together.
“Always pass on what you have learned.” said Yoda
