Motionbuilder to Unity: some of my joints are twisted

This is what our animation frame looks like a third of the way through our animation in Motionbuilder and in Unity.

All of our animations seem to be having problems like this - usually in the feet.
What are we doing wrong? Any ideas? Or could this be a Unity bug? I’ve attached the fbx.

[15586-jump.zip|15586]

So, Unity support got back to me and pointed out:

Problem is that the character is not in a good T-Stance when configuring the Avatar.

I have made a good T-Stance at frame 0 of this file… and the problem disappears.