VS Code not debugging with different angular configuration - visual-studio-code

Question

I created a new configuration in my angular.json and I cannot make VS Code debug.
My VS Code is debugging OK when I use the default configuration.
I created a new configuraton in angular.json as below:
{
...
},
"newProjectRoot": "projects",
"projects": {
"MyProject": {
"projectType": "application",
"schematics": {
...
},
...
"architect": {
"build": {
...,
"configurations": {
"production": {
...
},
"development": {
...
},
"fred": { <================================================
"buildOptimizer": false,
"optimization": false,
"vendorChunk": true,
"extractLicenses": false,
"sourceMap": true,
"namedChunks": true,
"fileReplacements": [
{
"replace": "src/environments/environment.ts",
"with": "src/environments/environment.fred.ts"
}
]
}
},
"defaultConfiguration": "development"
},
"serve": {
...,
"configurations": {
"production": {
"browserTarget": "fuse:MyProject:production"
},
"development": {
"browserTarget": "fuse:MyProject:development"
},
"fred": { <=====================================================
"browserTarget": "fuse:MyProject:fred"
}
},
"defaultConfiguration": "development"
},
...
}
}
}
}
On package.json I created a new script
"scripts": {
"ng": "ng",
"start": "ng serve --port 8093",
"start-fred": "ng serve --configuration fred --port 8093", <====================
...
}
On my launch.json I added a new config to start that script
{
"version": "0.2.0",
"configurations": [
{
"name": "ng serve Chrome",
...
},
{
"name": "Fred ng serve Chrome",
"type": "chrome",
"request": "launch",
"preLaunchTask": "npm: start-fred", <=================================
"url": "https://localhost:8093",
"webRoot": "${workspaceFolder}"
},
{
"name": "ng serve Edge",
...
}
]
}
It builds OK and I can navigate the app by manually going to the URL on the browser but I cannot debug. VS Code hangs with no error message and never starts the debug session.
I don't know where else to look. As I said before, I can debug OK when I use the default (development) configuration