-Q reproducer

;; The culprit appears to be `redisplay--update-cursor-face-highlight'
(setq debug-on-error t)
(cursor-face-highlight-mode)
(save-excursion (insert (propertize "cursor face text\n"
                                    'cursor-face 'region)))
(narrow-to-region (pos-bol) (pos-eol))
(setq unread-command-events (mapcar #'identity
                                    (kbd "C-n")))

-Stephane