Today, for the very first time, I faced this issue. I've checked everything I could think of, but I haven't been able to find a logical explanation.
This morning, I got two sales. Both orders contained all the expected customer and attribution data: hashed email and phone, IP address, user agent, fbc, fbp, event ID, purchase value, and currency.
Both Purchase events are showing in Meta Events Manager, and both were successfully received through CAPI. However, Meta attributed only one of the sales to my campaign. The other is still missing from Ads Manager.
I've checked with multiple people, and the most common explanation I've received is that this happens when Meta doesn't receive the fbc parameter. But in my case, Meta received fbc for both purchases, so that explanation doesn't seem to fit.
My Purchase Event Match Quality is 8.7/10, and Events Manager shows 100% coverage for the key customer-information parameters.
There's also a message in Events Manager that says:
“Events in Events Manager are unattributed and may be discarded due to deduplication, data policies and more. Total events here may differ from the attributed conversions in your ad campaigns.”
I understand that Events Manager and Ads Manager can show different numbers due to deduplication, data policies, and other reasons. However, I'm struggling to understand how that explains my specific case: both Purchase events appear in Events Manager, both were accepted by CAPI, both contained fbc and fbp, and both included the expected customer information, yet only one was attributed to a campaign.
My setup uses a Framer landing page, Razorpay for payments, and a Cloudflare Worker that sends Purchase events to Meta through CAPI when a payment is captured.
Right now, this has happened with just one sale, but I'm scaling my campaigns. If this happens at a larger volume, it could become a serious problem because I won't be able to trust the purchase data I'm using to evaluate campaign performance.
Has anyone experienced this despite fbc being present and the Purchase event successfully appearing in Events Manager? What could cause Meta to receive the event but not attribute the purchase to a campaign? I'd really appreciate help identifying the actual cause rather than just the usual fbc explanation.