We should move this discussion out of DTM and into Analytics if we continue beyond this comment. Your prop will expire on page view so if you want the list to match on instances it needs to expire on page view as well.
My understanding is that the list vars (list1, list2, list3) follow the same basic expiration rules as eVars. So if a list var is set to expire on the visit, then any value assigned to that var during the visit will persist until the visit expires. If it is set to a specific time period, like month, day, 5 days, etc, the value assigned to that list variable will persist for that specific time period, beyond the visit.