React still showing errors after catching with ErrorBoundary
Solution 1:
I think I got it. The create-react-app package has a tool called the react-overlay-error. This shows error messages from the console as an overlay over your app so you can easily check the stack trace and debug.
This won't show up in production mode, it's just a development tool duplicating the normal browser console.
You can hide this by pressing Escape to see your overlay again.
If you want to get rid of it, this answer may help.