Adding an emoji to a commit breaks the text field

Adding an emoji to a commit title makes the commit text field look weird when opening it again.

The steps to reproduce are pretty simple:

1. Create a commit message with an emoji (from the Mac's keyboard, not the :emoji: format from GitHub)
2. Commit
3. Open commit window again and start typing the new message. The text field's font changes, looking weird, with huge spaces between words and other formatting issues.

The issue occurs until I restart the app or reopen the repository window.

I've added screenshots of the first commit with an emoji and how the next commits look.
I was able to reproduce it using the latest version (2.3.x), but I didn't try with the older ones.