Bridge 2023 bug - adding title to tooltip broken

I have a script demo to add the dc:title field to the thumbnail tooltip. It works in Bridge 2022, broken in 2023.

#target bridge
if(BridgeTalk.appName == 'bridge'){
    var showTitleCmd = MenuElement.create('command', 'Show Title on Hover', 'at the end of Tools');
    
    showTitleCmd.onSelect = function(){
        
        showTitle = function(event){
            try{
                if((event.type == 'hover') && (event.object instanceof Thumbnail)){
                    var Thumb  = new Thumbnail(event.object.spec);
                    md = Thumb.synchronousMetadata;
                    md.namespace = 'http://purl.org/dc/elements/1.1/';
                    var ti = md.title[0] ? md.title[0] : '';
                    if(ti != '') Thumb.core.itemContent.tooltip ='Title: ' + ti;
                    return{handled:false};
                    }
                }
            catch(e){
                }
            }

        app.eventHandlers.push({handler: showTitle});
        var prefs = app.preferences;

        try{
            if(!prefs.ShowTooltips){
                prefs.ShowTooltips=true;
                }
            }
        catch(e){
            }
        }
    }