Repeated `<i>`/`<em>` tags without spaces produce broken Markdown

[ViktorSviridenko]

The issue

Example:

<i>1</i><i>2</i><em>3</em><em>4</em>

<hr>

<span><i>1</i></span><span><i>2</i></span><span><em>3</em></span><span><em>4</em></span>

Result:

Expected result:

_1234_

How the result is rendered by different software

VS Code:

markdown-to-jsx:

Obsidian: