Joint orientation is not imported

I’m trying to use one skeleton to drive multiple planes in-game. Problem came across when trying to work on some planes with angled wings. I have rotated the joints and freeze transformation so the flaps on wings rotate correctly, however, upon re importing, the orientation value seems to be lost. In unreal, the flaps are rotating as if I did not tweak the orientation. I have made sure that the joint hierarchy is identical on all the skeletal mesh before export. Only thing different is the translation and rotation of certain joints.

Am I missing a checkbox in fbx exporter? the translation value seems to have no problem but only the orientation of the joints seems to not be there.