Problems with interactive rebase & fixup

[Webmaster 33]

I have a problem with interactive rebase & fixup.
Using GIT 2.11.1 locally in Windows 7, Git Extensions 2.49.
Problem & screenshots posted here:
https://github.com/gitextensions/gitextensions/issues/3537


Doing rebase to merge the fixup commits.
I select an earlier commit, then select Rebase current branch on master.
In Rebase window I click Show Options, the tick Interactive rebase & Preserve merges options.
Click Rebase button.


Process dialog shows the following:

"git" rebase  -i --no-autosquash --preserve-merges "dc695e3a1e2080c69bbb1a31b435e268abdb7da0"

The following file content appears in my Notepad++ text editor:

noop

# Rebase dc695e3..5081303 onto dc695e3 (1 command(s))
#
# Commands:
# p, pick = use commit
# r, reword = use commit, but edit the commit message
# e, edit = use commit, but stop for amending
# s, squash = use commit, but meld into previous commit
# f, fixup = like "squash", but discard this commit's log message
# x, exec = run command (the rest of the line) using shell
# d, drop = remove commit
#
# These lines can be re-ordered; they are executed from top to bottom.
#
# If you remove a line here THAT COMMIT WILL BE LOST.
#
# However, if you remove everything, the rebase will be aborted.
#
# Note that empty commits are commented out

Then without ability to edit text, the file is deleted, and following result appears in the process window:

"git" rebase  -i --no-autosquash --preserve-merges "dc695e3a1e2080c69bbb1a31b435e268abdb7da0"
Successfully rebased and updated refs/heads/live_master.
Done
Press Enter or Esc to close console...

The result seems like if I had do a

git reset --hard "dc695e3a1e2080c69bbb1a31b435e268abdb7da0"

I can only restore the original state by resetting to remote HEAD.

"git" reset --hard "50813033ba413aeeef7dd509769cf947243d3911"
HEAD is now at 5081303 fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! fixup! Create bash script.
Done
Press Enter or Esc to close console...

Problem & screenshots also posted here:
https://github.com/gitextensions/gitextensions/issues/3537


Let me know if you need further info or tests.

Could be possible to fix this?
What can be the problem?