When you add Campaign Builder's feed as a supplementary feed (rather than replacing your Shopify catalog entirely), Meta merges the two feeds by matching each product's ID (retailer ID). Meta looks up the product ID from your primary Shopify feed and pulls in the matching row from the supplementary feed to add or override fields.
This means the two feeds need to agree on:
If either of those is off, products will silently fail to merge - they just won't pick up the supplementary data, with no obvious error on the ad itself.
Symptom: DPA ads are missing data, showing fallback content, or a chunk of your catalog just isn't eligible for dynamic ads.
Common cause: A mismatch in catalog scope. For example, your Shopify partner integration might sync ~1,500 SKUs while the supplementary feed contains ~3,000 SKUs - meaning there's a filter somewhere (published/unpublished status, specific collections, out-of-stock exclusions, or variant-level vs. product-level IDs) causing the two feeds to disagree on which products exist and how they're identified.
How to check it:
Fix: Once the filter or ID mismatch is identified, either adjust the Shopify integration settings to match the full scope of the supplementary feed, or ask Campaign Builder support to align the feed's ID format to your Shopify catalog.
Symptom: A 4:5 (or other non-square) placement shows an image that looks stretched or distorted, or shows a plain product photo instead of your designed ad creative.
There are two distinct causes here, and they call for different fixes:
Why this happens: This placement needs an image in a specific aspect ratio (e.g. 4:5). If the image on file for that placement is actually 1:1 (square) rather than the correct ratio, Meta will simply stretch it to fill the frame instead of showing it properly scaled - which is what produces the distorted look (e.g. a logo or icon that should be perfectly round or square appears warped).
How to check it: Confirm which image is assigned to the 4:5 (or relevant) placement and check its actual dimensions/ratio.
Fix: Upload or generate an image that's already in the correct aspect ratio for that placement, rather than relying on a 1:1 image being stretched to fit.
Why this happens: This is usually a feed-matching issue, and it's connected to Issue 1 above. If a SKU exists in your Shopify feed but has no match in the supplementary feed (because of the product count/filter mismatch described above), Meta has nothing to merge in for that product - so it falls back to whatever image is set on the base Shopify feed. That's typically just a plain pack shot (product on a white or plain background), not your designed dynamic ad creative.
How to check it: Look up the specific product ID from the ad in both feeds. If it's missing from the supplementary feed, that confirms the fallback.
Fix: Same fix as Issue 1 - once the feeds are aligned so every relevant SKU has a match, the correct creative will be pulled in instead of the fallback image.
Sending the details below with your first message will speed up troubleshooting significantly:
Reach out to your Campaign Builder contact with the checklist above filled in - it's usually enough to identify the root cause without back-and-forth.
