I have setup a number of simple queues as leaves, based on mangle marks. Half of the leaves are children of Critical and the other half of Global, the latter also being the parent of Critical. Global is therefore the only queue without a parent.
The leaves work as expected when their parents are disabled. When I enable them, however, the parents eat all of the traffic, leaving nothing whatsoever to their poor children.
I have been able to eliminate the problem by setting all leaf priorities lower than 8 and all parent priorities to 8. However, the question remains: Aren’t parents supposed to always be assigned a lower effective priority than their children? Unless I am mis-reading the manual, this may well be a nasty, ugly, family-undermining bug!