You have configured GA4 cross-domain settings, but bookings made through Track’s hosted checkout still do not get credit for the original ad click.
Why this happens. Cross-domain configuration stops the checkout round trip from splitting the guest’s session, but it does not restore ad-click credit on its own. Track’s checkout pages run on trackhs.com and do not load your website’s Google tag, so GA4 never sees the original ad click during the checkout flow.
What restores credit. Credit is only restored when the guest returns to a confirmation page on your own domain, where a purchase event can fire with the original attribution data.