List of steps to reproduce (step by step, including full links if applicable):

• Reply to a comment using the new reply feature
• Add text formatted with tags like <pre>, <code> or <syntaxhighlight>

What happens?:
The tool will add colons in front of the preformatted text, and there's nothing you can do to prevent that:
https://de.wikipedia.org/w/index.php?title=Wikipedia_Diskussion:Kurier&diff=prev&oldid=217156787

What should have happened instead?:
The tool should not add colons inside preformatted blocks