Because Aria uses the Space Mono font, </ is displayed as an arrow. It's probably wise to use CSS property "font-variant-ligatures: none;", like Copilot does for example.
See for example this image:
As you can see </ is displayed as an arrow, but when I copy the code, it does copy the correct code:
<div>
<h1>Welcome to my website!</h1>
<p>This is some exciting content.</p>
</div>
(Aria 6.1)