The symptom is similar to the experience reported with Social Oomph ("SO") Twitter earlier this year on Black Hat World. It's unclear from that thread how the issue was resolved.
I decided my issue was different.
I had more than two dozen contiguous posts to Facebook (mainly business pages) that failed over the past three weeks. All reported as successful through SO. The response from SO is a standard one (reproduced below).
The SO gateway to Facebook is much more convoluted than with Hootsuite or Sendible. SO claims this makes it better - indeed to avoid problems like this one.
Since the API tells SO the posts succeeded, a possibility is privacy settings in Facebook. And there was the tipoff: the Facebook app had remained in developer mode, which meant only the developer identity in Facebook could see the posts -- even though they had been issued. Yes, the error was mine in the app setup process. That said, the troubleshooting for this problem was unhelpful (i.e., non-existent).
When your list of tweets in SocialOomph say the tweet was published, then it means the tweet was successfully sent to the Facebook API and the API accepted it. The only condition where a tweet is marked Published is when the Facebook API said it received and accepted the tweet.
If it is not in your timeline it means it got lost somewhere inside the Facebook system. It is either a temporary glitch in Facebook, or Facebook suppressed the updates.
The best will be to ask for help from Facebook support staff.