I'll leave that till you see Sebastian, in case you have something in mind, and I can't remember how it was, but it looks to me like this should be bulletted as opposed to a code block.
This is indeed a problem we discovered when switching from the old wiki to the most current build.
The fix we found is to use slightly different tags for multi line code blocks:
Examples before/after here: https://wiki.apertus.org/index.php/Sandbox
It requires manually cleaning those affected pages though.