I've had the same frustration. The browsers have such great debugging features, in theory, but they never seem to work reliably. I can't even get all of my breakpoints to reliably hit.

Everything seems to work ok when the code is unrolled but as soon as it gets bundled, even if not minified, it seems that a lot of debugger features get broken, at least that's been my experience.

Note: I'm not a front-end engineer and I'm probably doing something wrong.