Incorrect handling of netrw window on session restore

Started learning vim just about month ago and now trying to have netrw file-browser window loaded with the rest of the session but not getting it back when the session is sourced. What I get is some real strange behavior depending on what window/tab is active when running :mksession command.

STEPS TO REPLICATE:

Start vim
Open netrw file-browser with ':e.'
Open any text file in a separate tab 'tabe .vimrc'
Run ':mksession' command
Exit vim
Load saved session with 'vim -S' or 'vim -S Session.vim'
RESULT: all windows from the session are there except netrw, but it is restored by sourcing the session again from inside vim with ':source Session.vim'.

The other way:

Start vim with a text file loaded like 'vim .vimrc'
Open netrw file-browser with ':vs.'
Run :mksession' command
Exit vim
Load saved session with 'vim -S' or 'vim -S Session.vim'
Run :mksession!' command
Exit vim
Load saved session with 'vim -S' or 'vim -S Session.vim'
RESULT: all windows from the session are loaded but netrw one is empty and no way to fix it.

Posted this one on vim_dev but have got no single response, so the questions here are "What am I doing wrong", "How to make it work" and "Why was my bug report totally ignored".

Vi IMproved 8.1

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