Role Assignment dates do not match Activity dates

I have had this specific issue in multiple projects over last couple of years using P6. I know this has been discussed a few times on these forums before with no apparent resolultion. Or none that I could find.

I have a schedule whereby roles are assigned to activities. When i F9 Re-schedule, the activity dates move, but not the dates of the role assignments to those activities. It seems as if there is a broken link between an activity dates and the role/resources assigned to it.

Members here have suggested the following before;

- Roles/Resources follow 'Planned dates'. I have checked Planned dates and the resource dates are not anywhere near those.

- Resource Calendars and Activity Calendars being different -  All my activities and resources/roles are using exactly the same Calendar.