A store owner we talked with this week had the classic shape of this problem: ad account spent a few hundred dollars, the store shipped four orders, and the purchases column in Ads Manager showed exactly one. Their response was to replace the pixel and the ad account — the most expensive possible answer to what is usually a measurement question. Before you do anything like that, spend two minutes counting, because which purchases are missing decides the entire diagnosis.
The Ads Manager purchases column was never supposed to equal your store's order count. It shows purchases attributed to that specific ad, within the account's attribution window — by default, people who clicked in the last 7 days or viewed in the last day. Orders from organic traffic, email, or a friend's shared link never belong in that column, no matter how healthy your pixel is. The number that should match your store is in Events Manager, which counts every purchase event from every source.
The two-minute count
Open Events Manager, select your dataset, and look at the Purchase event's total for the last 7 days. Put your store's order count for the same window next to it. Three outcomes, three different problems. If the totals roughly match, your pixel is fine — the gap you saw in Ads Manager is attribution, not tracking, and the missing orders simply came from somewhere other than your ads. If Events Manager shows close to zero while the store has orders, the purchase event never fires — that is a wiring problem. If Events Manager catches some but clearly not all, you are losing a share of events in transit — that is a coverage problem. Each of these has a different fix, and none of them is “new ad account.”
When every purchase is missing
A purchase event that never fires is almost always a page problem, not a pixel problem. The event has to run on the order confirmation page, and that page is exactly where standard setups break: the checkout happens on another domain and the buyer never returns to yours, or the platform's checkout does not execute custom scripts at all. On Shopify specifically, checkout pages do not run arbitrary pixel code you pasted into the theme — purchase tracking has to come through the Meta sales-channel app or a proper web pixel extension. The test that settles it: open Events Manager's Test Events tab, place a real test order yourself, and watch whether Purchase appears. If it does not fire for you, it fires for no one.
When only some are missing
Partial loss is the browser tax. A browser-only pixel silently loses the buyers running ad blockers, strict privacy settings, or iOS devices that cut tracking off — a meaningful share of real customers, and not a random one. The recovery is server-side events: the Conversions API sends the purchase from your platform's backend, immune to what the browser blocks. Shopify's Meta integration ships this — worth confirming it is actually on, because the difference shows up directly in how much signal your ad sets learn from. One caution while checking: browser and server events for the same order must carry the same event ID so Meta deduplicates them. Get that wrong and your problem inverts from undercounting to double-counting.
The most expensive response is the reflex one
Replacing the pixel or the ad account resets everything that was working: event history, learning progress, the audience data your account accumulated. It is the one move that reliably makes performance worse for weeks — taken in response to a number that was often correct all along, just answering a different question than the one being asked. Run the count first. If Events Manager matches your store, nothing was ever broken. If it does not, the fix lives on the confirmation page or in the Conversions API — both repairable in an afternoon, on the account you already have.