Let me start:

I have a React + Django API that sits behind Nginx that I'm trying to containerize with Docker. For some reason, React can't get pass the CORS policies of the API, even though I can manually open the API endpoints on my browser without any problems. I even tried using CURL and HTTPie to issue the requests, and I can successfully get the response with the appropriate Access-Control-Allow-Origin header.

The culprit? UBlock Origin tags the endpoint /api/ping/ (that is used within the API) as an advertisement server. Big yikes!