Debugging web-site not firing breakpoints using Edge

I have had this work in the past, but I'm currently experiencing a bizarre situation whereby I'm not hitting breakpoints on debugging using Edge.

Some points that I've established may be relevant during research (or just think are relevant):

• I'm running under IISExpress
• Works using Chrome
• In internet options, I've disabled the "Disable script debugging" options for both IE and others
• I am trying to debug typescript, but I get the same issue with a standard javascript file
• I'm using VS2017
• I am running in debug mode
• I can hit the same breakpoint using F12 dev tools, so the code does get executed (VS also makes the breakpoint hollow, indiciating it knows it can't break there)

I feel like I'm missing something, after all, surely Edge is the one browser that should debug with VS.