Cannot create Maya character definition from UE5 Mannequin

Hi guys,

Hope you can help, I have exported the UE5 manequin as an FBX file and imported it into Maya and so far so good. But…
I want to create a Human IK character definition in Maya for this skeleton.
If you´ve used Mayas human IK system you’ll know that you can create a new character definition and specify which bone from your skeleton corresponds to which bone in your human IK definition.
Once all the bones have been specified you then lock the definition and can share animations between this and other rigs.

The problem is that Maya cant seem to resolve the arm bones. This happens with most rigs and is generally solved by zero out the rotations on those bones. However, in this case that is not working.

So, has anybody managed to create a Human IK character definition in Maya from the UE5 Skeleton and if so, how did you get round the issue I have here?

Thanks for any help you can offer on this.