Problems with TkFixedFont (on Mac)

The following lines of code:

from tkinter import *
win= Tk()
text= Text(win, height=15, font=('TkFixedFont', 18))
# text= Text(win, height=15, font=('Courier', 18))
text.insert(INSERT, "arrow-left: \u25c4, arrow-right: \u25ba")
text.pack()
win.mainloop()

Gives me this result:

I would expect the font to be monospaced and arrows equal in size.
MacOS Ventura 13.1, Python 3.11.1, tkinter 8.6.12
Thanks for help and advice