No routes resolve on SPA with React-router

My Netlify instance: . Everything’s been working swimmingly except now, for some reason, none of the routes that serve using react-router are picked up, they all go to the default Netlify “Page Not Found” page. The root works normally. See for yourself:

Looking at the console, it seems that my app is not loaded AT ALL, so this seems like some kind of domain name issue maybe?

Routes work as expected on my local dev machine. What else can I look for or try?

Seems like you’re missing the required SPA redirect on that site:

Ah ok—I didn’t realize I needed to do this. Thank you!