React app renders blank after build, but can see DOM tree and there are no errors

I have no idea what I broke. When I run the server and app separately, I can see what I’m supposed to see on the web page but when I build the front-end app, I just see a white page but with correct DOM tree in the console.

Things I’ve tried:

Add “homepage”: “.” to package.json

Clean App.js completely and only render a small piece of text