There are 24570 code characters in that topic, and unfortunately it’s quite common for Android phones to struggle rendering those. You will see the same thing if you try to see a large diff on GitHub.
We added a limit so we don’t highlight code blocks large than 30k characters, but the ones on that website are smaller so they render fine on desktop but struggle on lower powered devices.
It’s on our long term roadmap to run the highlight code in a background thread, but we are not there yet.