How to debug Ionic4 with WebStorm?

Hi,
I can’t debug an Ionic4 app with WebStorm, because the breakpoints don’t work.
To configure the system I have done these things (according to this article):

On Ionic app:

  • Added the entry “start”: “ionic serve” in package.json,
  • added “sourceMap”: true in tsconfig.json,

On Chrome:

  • installed and enabled the WebStorm plugin,

On WebStorm:
– added a new Javascript debug configuration with URL: http://localhost:8100

When I launch the debug, it opens the app into Chrome, in the WebStorm console I can see these messages:

> ionic serve
Debugger listening on ws://127.0.0.1:51405/19a574a3-dc1d-41c9-90a5-2c616834feb5
For help, see: https://nodejs.org/en/docs/inspector
Debugger attached.
> ng run app:serve --host=0.0.0.0 --port=8100
[ng] Debugger listening on ws://127.0.0.1:51414/8a517b94-5de8-415e-9f30-1330e343e179
[ng] For help, see: https://nodejs.org/en/docs/inspector
[ng] Debugger attached.
....

But the breakpoints don’t work.
Which could be the problem?

cld