I have an issue where one pick list is filtering another one.
In my case, I have a "Division" list filtering my Services and Teams in a task.
When I create a new task, Division A is selected as default, Service shows only Division A's services, and Team shows only Division A's teams.
When I change my Division to Division B, the Service list doesn't get refreshed with Division B's services (My Division A services are still there), but the Team does get refreshed properly.
But still, I can force the values in it as long as I know exactly the Services that should be available on the list, or leave the "non-valid" one from Division A.
Both lists are "Ignore constraints if empty...", "Auto-select if only one record..."