Infinite sockjs-node xhr_streaming error - but not when in incognito

I have a CRA (not ejected) and it just infinitely makes `eventSource` and `xhr_streaming` 404 errors (see image below). The app is not ejected.

I have package.json `proxy: <my api server>`. 

The thing is, I do not have this error when I'm in incognito mode. 

I can provide more details, but I'm hoping someone can give me an idea of what this might be. 