Delete iCloud note with an attachement keep the file in a Library sub-folder

Hi,

using Numbers, i tried to sent a spreadsheet to a Notes.

A note was created with the attached Numbers file.

This one was correctly sync witth iCloud.

Then I deleted the note twice : also from the Notes trash because I did not want to wait 30 days.

Again, sync was OK. The notes were gone.

The problem :

I am still able to find my atteched file inside a Library sub folder : Library/Group Containers/group.com.apple.notes/Media/6C0259D3-0BF4-46ED-964F-7D4D5BFE7C76/

Is that a bug ? What about security and confidentiality if my OS does not delete the file as I request ?

Thanks for any explanation.