In markdown mode each paragraph line is serialised before parseBlockMD joins them, so $x$ inside a ``` fence became data-mx-maths markup inside the resulting <pre><code> (rendered as math in a code block). Track fence state across lines and skip math for fenced lines and for backtick code spans. Unit tests added; verified in the browser. Also: scripts/dev-homeserver.sh enables MSC4140 delayed events so scheduled messages work locally. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01PPmy3tPq869XDW4njjVaKA