If you're seeing Add to Cart events in Events Manager (Pixel/API), but not in Ads Manager, it usually comes down to how Meta attributes those events to ads. Here's what's going on:
Key Reasons for the Discrepancy:
1) No Attribution to Ads
Events Manager shows all Add to Cart events, whether or not they came from ads.
Ads Manager only reports events attributed to ad clicks or views within your attribution window (e.g., 7-day click / 1-day view).
2) Pixel/CAPI Events Not Linked to Campaigns
If the Add to Cart event was triggered by organic traffic, direct visits, or other sources, they’ll show in Events Manager but not in your campaign data.
3) Wrong Optimization Event
If your campaign is optimized for purchases, Meta may not always surface Add to Cart metrics unless you select them manually in Ads Manager.
4) Attribution Window Mismatch
If users added to cart outside your campaign’s attribution window, the action won’t be tied to your ad.
5) Event Deduplication Issues
Pixel and Conversions API might be firing together, but not properly deduplicated, leading to double or misattributed data.
