It depends on how you created your 2D objects.
If the 2D content is entirely in the 2D Symbol window (drawn there, or pasted from elsewhere), then you need to verify the pens used for the elements there.
If the 2D content is scripted in the 2D Script, then you need to modify the PEN commands.
But, in any case, when you place any object, the object tool lets you choose to use the pens of the object or to OVERRIDE them with a single pen. Make sure you have the proper setting selected.
Finally, if your display options must be set to True Weight, of course.
HTH,
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sequoia 15.2, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB