RTP / Facebook Custom Audiences
Last week we enabled Facebook retargeting custom audiences using RTP data. We created 3 custom combinations with the following segmented audiences. When we enabled the audience, we initially saw 30 people in the first bucket, but a day later they all disappeared. We've adjusted the retention window to 180 days, and still no luck with any of the audiences. See below:

I understand match rate is lower for Facebook (we typically see about 5%), but the fact that we're not seeing ANY matches in Facebook leads me to believe there is something wrong with the integration or perhaps the way we configured the segments (although - we followed the documentation step by step). We also don't have a problem with Google.
We seemed to have stumped support, so I wanted to ask if anyone else has found success with the Facebook retargeting integration? Is there anything glaringly obvious that we're missing?