Visitors, who qualify for a segment created in Adobe Audience Manager in the current session, will not qualify for it in Adobe Target until the Target session expires and they come back.
Adobe Audience Manager
This behavior depends on a setting of the integration between Adobe Target and Adobe Audience Manager in the backend. In this case, it is configured that Target will check Adobe Audience Manager segments once per session instead of in real time. It is managed by Adobe, and you cannot change it in the UI.