Nix / NixOS

I've been having trouble rebuilding my system for a few days now. The issue seems to be that a commit to nixpkgs-xr/xrizer added an aarch64 patch. There's been a commit that removes this patch but I can't seem to pull it with nix flake update which makes me think my flake might never have been working properly (although I'm getting the home-manager, stylix and unstable packages I've selected). Could someone please review my flake.nix and tell me if I'm doing something wrong?

{
  description = "Core Flake";

  inputs = {
    # Official NixOS Packages v25.11
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.11";
    home-manager = {
      url = "github:nix-community/home-manager/release-25.11";
      inputs.nixpkgs.follows = "nixpkgs";
    };

    nixpkgs-xr.url = "github:nix-community/nixpkgs-xr";

    unstable = {
      url = "github:NixOS/nixpkgs/nixos-unstable";
    };

    stylix = {
        url =  "github:nix-community/stylix/release-25.11";
        inputs.nixpkgs.follows = "nixpkgs";
        };
  };

  outputs = inputs@ { nixpkgs, nixpkgs-xr, unstable, home-manager, stylix, ... }: {
    nixosConfigurations.nixos = nixpkgs.lib.nixosSystem {
      modules = [
        # Import my existing configuration.nix
        ./configuration.nix

        nixpkgs-xr.nixosModules.nixpkgs-xr

        home-manager.nixosModules.home-manager
        {
          home-manager.useGlobalPkgs = true;
          home-manager.useUserPackages = true;
          home-manager.users.professor = import ./home.nix;
        }

        stylix.nixosModules.stylix

        {
        nixpkgs.overlays = [
          (final: prev: {
            unstable = import unstable {
                inherit (final) config;
                inherit (final.stdenv.hostPlatform) system;
                };
          })

        ];
        }
      ];
    };
  };
}