1) Like many others (I'm guessing), I haven't had this issue, so I can't help from experience.
2) This forum exists because all WordPress add-ons have one. Users can visit the forum to share experience. Authors aren't obligated to use the forums. Most of us are the Wordfence freeloaders with no expectation of free support from Wordfence. Wordfence is in the business of making money by selling enhanced features and support.
Seeing how I have not run across this issue, I have two suggestions:
1) Go to Wordfence options and enable "Delete Wordfence tables and data on deactivation?" Then deactivate and delete the Wordfence plugin. And reinstall.
2) It *could* be a conflict with another plugin. Disable all other plugins and see if the problem persists.
As for blocking spam, I use Akismet and it works pretty well…especially against bots.
I also use http://perishablepress.com/wordpress-5g-blacklist/ that also does a good job of blocking bots. You can also try the Bad Behavior plugin.