Saving as PDF includes Illustrator layers when "Create Acrobat Layers from Top-Level Layers" is turned off
I often iterate ideas on multiple layers, then use the "Save as PDF" option to export a clean version with inactive/hidden layers omitted using "Create Acrobat Layers from Top-Level Layers" de-activated.
However, I have noticed recently that when I re-open PDF files saved in this manner, the hidden Illustrator layers are still present, when the hidden data should have been omitted from the PDF.
Please correct this, as it's causing Illustrator to generate PDF files that are larger than they need to be, with the inclusion of hidden layers, which may also include reference images and templates not needed in the output.
Egor Chistyakov commented
Do you have it Compatibility option turned on (no bug, if yes) or off (then bug)?