(note someone marked this thread resolved, which it is not)
To be even more specific the installation instructions read:
1. Install Facebook for WordPress either via the WordPress.org plugin directory, or by uploading the files to your server (in the /wp-content/plugins/ directory).
2. After activating the plugin, you will be asked to set up your Facebook app (via http://developers.facebook.com/apps), with step-by-step instructions.
3. That's it. You're ready to go!
1 & 2 both done, but that does not yield the result in step 3
Furthermore, the instructions do not mention anything about configuring options, in this cases specifically setting up comments
Check the box for comments (done)
set the number of existing comments (done set at 40)
set the width of the comment box in pixels (done set at 600)
set the color scheme (done set at light)
result no comments displayed on single post pages
attempted to change width to 600px instead of 600 on the off chance that the instructions are lacking (ergo user error from bad guidance)
result is that an error message popped up stating that indeed only an integer value would be accepted
still no comments
changed color scheme to dark
I do run the site on cloudflare, and did test with all cache turned off by running the site in development mode
result no change, no comments
Also the Facebook Comments plugin works fine on the same site running the same working Facebook app.