With the release on September 14 (read more here) , Target will change the way users are placed into experiences in Experience Targeting (XT) activities (Landing Page campaigns in Target Classic). For all new and existing activities in both Target Standard/ Premium and Target Classic, users must meet the experience targeting rules on every impression to continue to see the experience's content and to be counted in reports. Previously, if the user no longer qualified for any experience, the user would continue to see the content from, and be counted in reports for, the last experience they did qualify for.
This change will happen automatically ads part of the release for all existing activities and for any new activities created post-release. If the previous method (prior to September 14) is desired, you can create audiences using profile scripts so a user only must meet a condition once to conitnue to fall into that audience in the future. Then, use those audiences for each experience in the activity.