Originally Posted by
ijgordon
I assume it's related to the tag-on BA-operated flight, which is NOT flagship business, and due to said IT glitch, suppresses the "flagship" part of the class of service on the entire itinerary.
Not only do partner connections not show "Flagship" but it can also vary depending on whether you're searching for award or paid tickets, which leads folks to the inevitable conclusion that you get "Flagship" benefits on paid flights but not award flights.
Just terrible AA marketing consistency combined with terrible AA IT.