This query returns a list of subtasks assigned to me.
assignee = currentUser() AND type in subTaskIssueTypes()
However, this one does not even though I KNOW that one of my Subtasks is in an open Sprint. I can see the sprint value on the issue detail view.
assignee = currentUser() AND type in subTaskIssueTypes() AND Sprint in openSprints()
Why are subtasks not indexed by Sprint Value?