Hello -
I also believe that there is nothing wrong with the FBX Exporter in DAZ Studio. There is something that is non-standard with the skeletal skin binding that is done in DAZ when compared to the same setup done in either Max or Maya. This is why the workaround of importing into Maya and Max allows the skeletons to be exported using those program’s formatting which UE4 understands.
In either case though, the bug itself will not and has not been closed, it is backlogged which may mean it will take a significant amount of time for us to get to, which is why I suggested reporting the issue to DAZ as a way to get two entities aware of the issue.
Thank You -
Eric Ketchum