bug#45915: 28.1; delete-char deletes two letters

[Tak Kunihiro]

As Ihor pointed out, delete-char deletes two letters.

Can someone take a look and evaluate if this is issue with delete-char?
I simplified the recipes as shown below.

#+begin_src emacs-lisp
(defun emacs-bug-reproduce-45915 ()
  "Reproduce bug#45915."
  ;; (gnus-read-ephemeral-emacs-bug-group 45915)
  (interactive)
  (with-current-buffer (get-buffer-create "*temp buffer*")
    (erase-buffer)
    (require 'org)
    (orgtbl-mode 1)
    (insert (format "emacs-version: %s, org-version: %s\n" emacs-version 
org-version))
    (insert "| 1 |"))
  (switch-to-buffer-other-window "*temp buffer*")
  (execute-kbd-macro (kbd "M-< C-n C-f C-f"))
  (message "I will hit <S-return>.")
  (sit-for 2)
  (execute-kbd-macro (kbd "<S-return>"))
  (sit-for 2)
  (message "I will hit <delete>.")
  (sit-for 2)
  (execute-kbd-macro (kbd "<delete>"))
  (message "Two letters were deleted unexpectedly."))
;;; (call-interactively 'emacs-bug-reproduce-45915)
#+end_src