Help with missing symbols after setting monospace font

After setting monospace fonts to nerd-fonts.fira-code im seeing some missing symbols, what should i do?

example missing symbol:

Here is my nixos repo
Here is the config for stylix (where i set the monospace font):

{
  config,
  lib,
  pkgs,
  inputs,
  ...
}:
let
  cfg = config.modules.stylix;
in
{
  options.modules.stylix.enable = lib.mkEnableOption "enable stylix module";

  config.stylix = lib.mkIf cfg.enable {

    ## temp untill 25.05 release of stylix
    # https://github.com/nix-community/stylix/issues/1277
    enableReleaseChecks = false;

    enable = true;
    autoEnable = true;
    polarity = "dark";
    base16Scheme = "${pkgs.base16-schemes}/share/themes/catppuccin-mocha.yaml";

    image = ./barn.png;
    # image = pkgs.fetchurl {
    #   url = "https://gitlab.com/Felipe-Pinto/wallpapers/-/blob/e173091770ecf5a911f6f01f9b7dafc23081f4bc/series/steven%20universe/barn.png";
    #   hash = "sha256-0hnrxU5NSJRSKbQHZDkyf1Fl8BrIOyUMND7AFTitlNM=";
    # };

    # targets = with config.modules; {
    #   yazi.enable = yazi.enable;
    #   tofi.enable = tofi.enable;
    # };

    opacity = {
      applications = 0.9;
      desktop = 0.9;
      popups = 0.9;
      terminal = 0.9;
    };

    cursor = {
      package = pkgs.bibata-cursors;
      # name = "Bibata-Modern-Amber";
      name = "Bibata-Modern-Classic";
      size = 24;
    };

    fonts = {
      sizes = {
        terminal = 14;
        desktop = 14;
        applications = 14;
        popups = 14;
      };
      sansSerif = {
        package = pkgs.source-sans;
        name = "SourceSans3";
      };
      serif = {
        package = pkgs.source-serif;
        name = "SourceSerif4";
      };
      monospace = {
        package = pkgs.nerd-fonts.fira-code;
        name = "FiraCode Nerd Font";
      };
      emoji = {
        package = pkgs.nerd-fonts.fira-code;
        name = "FiraCode Nerd Font";
      };
    };

    targets =
      lib.genAttrs
        [
          "nixvim"
        ]
        (_: {
          enable = false;
        });
  };
}