Highlighting falls over after the first JSX fragment in my Javascript files.

The files I've tried also don't have any results on the Symbols view.

Example file: https://github.com/exultrochester/exultrochester.org/blob/master/src/pages/2018.js

(For context: create-react-app no longer supports craeting .jsx files because the .js/.jsx distinction is "not that useful anymore" as of 2016.)