I'm following the guide to contribute, setting up Visual Studio Code. My goal is to step debug a file,

src\Umbraco.Core\Xml\UmbracoXPathPathSyntaxParser.cs

Can someone give me a tip on how to achieve that? I can run/start debugging with F5 with the preset launch/task for VSCode. But I can't set a breakpoint and have an effect anywhere. I've tried in ContentSavingNotifications for example, but no luck.