Unable to make unique nested component

Sketchup 2021 21.0.338
Sketchup doesn’t want to make a nested component unique.
While it is okay for a non-nested component.
Why?
It worked well in previous versions of sketchup


ESSAI RENDRE UNIQUE.skp (135,1 Ko)

The only way I can find is to lock the first component so that sketchup will offer to make the second unique.

It’s because the parent components are instances of the same component. Make one of the E1 components unique and you can make the piece inside unique. Basic component behavior stuff.

Ok, i understand.
Thanks Dave