Dots showing up for some modules

[eddien24]

I'm using NixOS and Home Manager for my configuration. I've set up waybar as follows:

programs.waybar = {
    enable = true;
    style = ./style.css;
    settings = {
        ...
        cpu = {
          interval = 30;
          # format = "  {}%";
          format = "help";
          max-length = 1;
        };

        memory = {
          interval = 30;
          # format = "  {}%";
          format = "sadness";
          max-length = 1;
        };
        ...
    };
};

The generated ~/.config/waybar/config seems to be valid.

...
"cpu": {
      "format": "help",
      "interval": 30,
      "max-length": 1
},
...
"memory": {
      "format": "sadness",
      "interval": 30,
      "max-length": 
},
...

However, these modules only show dots.

Any ideas as to what this might be? Thanks!

[eddien24]

Removing the max-length line in my .nix worked.