It would seem that ReactJS is having the same problem Java is having today where the code editor is not accesible, no one can type in the code editor, and past code is shown as correct or passed but the code does not show up. You can read about the different issues in Java here: https://discuss.codecademy.com/t/java-lessons-suspended/70811/7 and here: https://discuss.codecademy.com/t/java-intro-lesson-1-no-code-in-code-editor-box-cant-complete/70835
I would suggest filling out a bug report to codecademy and just waiting to see what happens! For right now maybe try another language?