IconMenuItem symbol not found error

Hi I've never touched coding in my life but am trying to make a Garmin app. U had everything running fairly smoothly up until I wanted to add Icons into my menu2 screen. It functioned fine with just MenuItem, and the icons I want to use have been used on other screens within the app without issue.

I'm using whatever the most recent SDK is and was using api 4.0.0 then bumped it up to 5.0.0 but saw no changes.

Any help is much appreciated!!

using Toybox.WatchUi;
using Toybox.Application;

class TimerMenuView extends WatchUi.Menu2 {
    function initialize() {
        Menu2.initialize({
            :title => "Select Timer"
        });

        var breathIcon = Application.loadResource(Rez.Drawables.breath_32);
        var historyIcon = Application.loadResource(Rez.Drawables.history_32);

        addItem(new WatchUi.IconMenuItem(
            "15 seconds",
            null,
            :fifteen,
            breathIcon,
            null
        ));
        
        addItem(new WatchUi.IconMenuItem(
            "20 seconds",
            null,
            :twenty,
            breathIcon,
            null
        ));
        
        addItem(new WatchUi.IconMenuItem(
            "30 seconds",
            null,
            :thirty,
            breathIcon,
            null
        ));
        
        addItem(new WatchUi.IconMenuItem(
            "60 seconds",
            null,
            :sixty,
            breathIcon,
            null
        ));
        
        addItem(new WatchUi.IconMenuItem(
            "History",
            null,
            :history,
            historyIcon,
            null
        ));
    }
}