Sessions and persisting buffers does not work properly

Hi.
First of all, cool plugin, thanks for your work.

So, im using Sessions with ":SSave", ":SClose", "SDelete" and so on.

Expected behaviour: When I using a session (open some buffers, close others) and the I close vim, the last buffers I use in that session persist, and the ones that i close, don't persist.

For this, I using this variable in my .vimrc file:
let g:startify_session_persistence = 0
witch I believe, is the default value, allowing to save session on close.

But when I reopen the same session after I close vim, get open some unnecessary buffers.
I try to close the buffers with :bd and :bw before i close vim, but with the same results.
It's like the session is persisting with all the buffers listed with :ls! (ofc, including the hidden or unlisted buffers).

So every time a want to use a session, it's just get more and more unnecessary buffers loaded.

Im using vim 8.2

Start by reproducing the session workflow in Vim 8.2 with the .vimrc setting g:startify_session_persistence=0, using :SSave, :SClose, :SDelete, :bd, and :bw. Inspect how session persistence handles hidden and unlisted buffers; done means reopening a session restores only the buffers still open when Vim was closed.