It renders correctly on the web as well for me.

But the ``` being on their own line is how to write it properly, as stated this website among many others.

This way, you can put the intended programming language on the same line as the first ```, ensuring proper colour coding!

Ex.

echo "Hello $name\n";

echo "Hello $name\n";

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EDIT I checked on mobile, it rendered odd on Jerboa for me:

Now it is fixed: