200 OK… But Nothing Loaded, My CORS Debugging Story

I ran into something recently that didn’t make sense at first. My React app was working fine on Vercel. The page loaded, everything looked clean, no errors. Then I decided to improve it a bit ,instead of hardcoding my “About the Founder” section, I moved the data into a JSON file hosted on Amazon S3.It felt like a simple upgrade.That’s when everything stopped working. The request itself looked successful. No network failure, no broken endpoint. But the UI just refused to show the data. It was li