Full Answer

The customer journey did not vanish — it was split into disconnected fragments that analytics can no longer stitch together.

Here is what happens technically. A visitor arrives at your WooCommerce store on day one. GA4's JavaScript sets a _ga cookie identifying this visitor with a unique client ID. Over the next two weeks, the visitor returns four times — browsing products, comparing prices, reading reviews. Each return visit is connected to the same client ID via the _ga cookie.

On day eight, Safari deletes the _ga cookie because it was set by JavaScript and has exceeded the seven-day ITP limit. When the visitor returns on day nine, GA4 generates a new client ID because the old cookie is gone. GA4 now sees two separate users: one who browsed for seven days and left, and a new user who appeared on day nine.

If the customer finally purchases on day fifteen, GA4 attributes the conversion to a user with a one-day journey — because the current cookie was set on day eight. The thirteen days of browsing behavior that preceded the purchase are attached to a different, now-disconnected client ID.

The business impact compounds across your customer base. High-consideration products with longer purchase cycles — furniture, electronics, B2B services — suffer the most because their typical customer journey exceeds seven days. GA4 systematically undercounts the touchpoints that influenced the purchase and overcounts single-session conversions.

Server-side cookies set via HTTP headers from a first-party domain are not subject to the seven-day cap. They persist for their full configured lifespan, maintaining the continuous customer journey across weeks or months of consideration.