Hey there,

1. every InDesign Version (my Version Adobe InDesign CC 2018 13.1)

2. a) open new print CMYK document
   b) place a Ai object like .eps or .ai with RGB modus (with a black element – in RGB 0/0/0 – but in CMYK 88/79/65/93)
   c) now copy the object and convert the same object into CMYK modus and place them too
   d) start the CMYK separation preview in InDesign and disable the black color
   e) at the end only the CMYK object is separated and the RGB object is totally away

3. I wish the RGB object would separated like the rectangle – with the same color – next to the GTIN.

4. The RGB object doesn't separated like the CMYK object with the same color.

5. Screenshot

Kind regards and big thanks!