New ECID stitched to qualified profile still doesn't show Target experience until the qualifying event fires again (Edge Segment, authenticated site)

To add on top of it
Is this normal behavior for Edge Segmentation? Does it only check events it sees happening live on that exact ECID, and not look at the full history of the profile it just got linked to? Is there any setting to fix this? Or should we use a Profile Attribute instead of an Edge event rule, so new devices/browsers don't have this problem?

HI ​@TanviSi2 ,
I would not describe this simply as "Edge Segmentation only sees events on that exact ECID." The key distinction is whether the authenticated person identity and its profile data are available to Edge when Target makes the personalization request.

Adobe's Target guidance specifically notes that, for first-login personalization, if the request uses an ECID or another identity that is not yet stitched to the known customer profile on Edge, previously ingested profile data may not be available on the first request. It can take several minutes for the stitch to be realized on Edge, and historical profile data may become available on a subsequent page view. Therefore, a realized status in the Hub Profile does not, by itself, prove that the first Target Edge request could read that audience membership. The behavior described is consistent with an identity/Edge-profile availability gap, but the post alone cannot confirm the exact root cause. https://experienceleague.adobe.com/en/docs/blueprints-learn/architecture/use-case-patterns/personalization-patterns/audience-sharing-with-target

https://experienceleague.adobe.com/en/docs/experience-platform/identity/features/identity-graph-linking-rules/namespace-priority

What I would check first: On authenticated Web SDK events, verify that the stable person ID (for example, your CRM ID) is included in identityMap as authenticated and primary, with the ECID also present. Ensure the person ID is present on the first post-login personalization request and subsequent authenticated events, and that exactly one identity is marked primary. Compare the failing and successful Assurance traces: which identity was primary/requested, whether the Edge Profile lookup returned the expected membership, and whether Target marked the AEP segment as matched or unmatched. https://experienceleague.adobe.com/en/docs/experience-platform/collection/identity/identity-map https://experienceleague.adobe.com/en/docs/blueprints-learn/architecture/use-case-patterns/personalization-patterns/audience-sharing-with-target

Would a profile-attribute-only segment fix it? Not necessarily. Adobe documents that an audience containing only profile attributes is evaluated daily in the Edge segmentation guidance, so it is not a drop-in fix for same-page or next-page real-time qualification. A durable profile attribute may fit if the qualification is meant to persist across browsers/devices, but confirm that it is available through the Target/Edge implementation and that its evaluation timing meets the use case. https://experienceleague.adobe.com/en/docs/experience-platform/segmentation/methods/edge-segmentation

What are you sending as primary identity? ECID or your customerID? I had cases where we sent the ECID as primary, and the personalization did not work in realtime. Switching the primary identifier to the customerID (no stitching required) solved the problem for us. Should also be possible on your end, as you said the user is authenticated.

ECID is the primary id.