Shopify shows post-purchase offers to roughly 60–80% of qualifying orders — never 100%. This is by Shopify's design, not Oxify's.
Three Shopify-side requirements
Supported payment method — Some payment methods don't allow modifying the order after authorization. Those orders skip post-purchase.
No manual review hold — If Shopify flags the order for fraud review, the post-purchase flow is skipped to avoid complications.
Buyer didn't abandon — If the buyer closes the tab or navigates away mid-flow, no offer renders.
What this means for you
Don't expect 1:1 attribution. If you have 100 qualifying orders in a day, you might see post-purchase impressions on 60–80 of them. That's normal and expected.
Compare to Oxify-side filtering
Separately, Oxify may skip an offer if hide-if-in-original-order, hide-when-OOS, or trigger filtering applies. Those are configurable in your funnel.