font-lock breaks mdicons

I can use nerd-iicons-insert-mdicons in order to insert an icon, but when the font of the icon changes (say I add a comment) the icon breaks.

This only happens for Material design, all other icons work well. I have the fonts installed, because mdicons work in the preview and when I use the 'default face. If I remove the face, the error unicode character sometimes transforms back into the correct icon, but I can't reliably produce this.

Image: nf-bug-cropped

Here are the steps to reproduce it

Arch Linux, kernel 6.3.1
GNU Emacs 28.2
harfbuzz 7.3.0-1
cairo 1.17.8-2

init.el

;;;; Bug with nerd icons
(defvar bootstrap-version)
(let ((bootstrap-file
       (expand-file-name "straight/repos/straight.el/bootstrap.el"
             user-emacs-directory))
      (bootstrap-version 5))
  (unless (file-exists-p bootstrap-file)
    (with-current-buffer
    (url-retrieve-synchronously
     "https://raw.githubusercontent.com/raxod502/straight.el/develop/install.el"
     'silent 'inhibit-cookies)
      (goto-char (point-max))
      (eval-print-last-sexp)))
  (load bootstrap-file nil 'nomessage))

(straight-use-package '(nerd-icons :type git
                   :host github
                   :repo "rainstormstudio/nerd-icons.el"))

(require 'nerd-icons)

keyboard-macro

(fset 'nerd-icons-bug
      (kmacro-lambda-form [?\C-x ?\C-f ?t ?e ?s ?t return
                 ?\M-x ?e ?l ?i ?s ?p ?- ?m ?o ?d ?e return
                 ?\M-x ?n ?e ?r ?d ?- ?i ?c ?o ?n ?s ?- ?i ?n ?s ?e ?r ?t ?- ?m ?d ?i ?c ?o ?n return
                 tab ?- ?a ?t return return ?\;
                 ?\M-x ?n ?e ?r ?d ?- ?i ?c ?o ?n ?s ?- ?i ?n ?s ?e ?r ?t ?- ?m ?d ?i ?c ?o ?n return
                 tab ?- ?a ?t return return] 0 "%d"))

L.E. I have tried this on different computers, with different themes, and I get the same behavior.

rainstormstudio / nerd-icons.el

font-lock breaks mdicons #34