I came across this answer, which in my browser is rendered as:
I.e. code blocks are rendered as if they were enclosed in
But if I try to edit it, what I see is:
Code blocks are already enclosed in handlebars and the preview is rendered as expected.
I checked with both Chrome and Firefox, it doesn't look like a browser-related issue.
Since I cannot directly edit the post, I did not try to change something and save it (to check whether it is some kind of caching issue).
What is going on here?