Draft of a Part Copy linked to an assembly with fillet weld cannot be updated

In this scenario, the user has created fillet welds in a weldment assembly and then created a Part Copy of this assembly.

The Part Copy is to create a reference of the component after manufacturing.

When they open the related part Draft derived from the Part Copy, they observe that there is the grey corner visible on all views.  These grey corner normally indicate that the 3D structure is not updated.  However, in this case the structure is up to date.

In this instance, the reason the Part Copy.dft shows a thick border is because the Part Copy.par is out of date.  If the Part Copy.par is opened, it always prompts with the update link dialog. Consequently, it looks like there is an issue with a Part Copy feature.

By opening the assembly and recomputing the fillet welds,

save, close, open the part file, Update Link, save, close.

Then, open the draft file - the thick border will be gone and the drawing update can be executed without problem.