This here is apparently the original source of the markdown specification, and there it clearly says that this is the correct behaviour: https://daringfireball.net/projects/markdown/syntax#list

Ordered lists use numbers followed by periods:

Bird

McHale

Parish

It’s important to note that the actual numbers you use to mark the list have no effect on the HTML output Markdown produces. The > HTML Markdown produces from the above list is:

If you instead wrote the list in Markdown like this:

Bird

McHale

Parish

or even:

Bird

McHale

Parish

you’d get the exact same HTML output

[–] WhyJiffie@sh.itjust.works 1 points 21 hours ago (1 children)

hmm, you are right. it's not actually a bug in the renderer then

[–] squaresinger@lemmy.world 1 points 21 hours ago* (last edited 21 hours ago)

The only difference to the standard that I see is that the standard says it should be 1,2,3,4,5, while at least for me it renders as 5,6,7,8,9.

But that's probably because it doesn't render as HTML and thus doesn't rely on HTML to do the numbering.