smb conf – How is the samba recycle bin supposed to work with the deleted folders?

vfs object = recycle in smb.cfg works fine for deleted files.
However, how is the samba recycle bin function supposed to work for folders?

I made the following observations:

with option recycle: keeptree = yes

1 – delete a file – move it to the recycle bin, keeping the original folder structure

2 – delete a folder that contains a file – it will move it, and the files below it to the recycle bin, keeping the structure of the original folder

3 – delete a folder that does not contain files – The folder disappears, nothing in the recycling bin.

without option recycle: keeptree = yes

4 – delete a file – move it to the recycle bin without the folder structure

5 – delete a folder that contains a file – Folder and files disappear, nothing in the recycle bin.

6 – delete a folder that does not contain files – The folder disappears, nothing in the recycling bin.

Question: Are cases 3.5 and 6 according to design?

Thank you
Dan