I took a look at your note and I can see what's wrong. The parser that the editor uses is very limited, so anytime it sees text between angle brackets it will stop treating the text as markdown and start treating it as html. In your case you have <WAN-IP> in the note. This is wrongly interpreted as an HTML code and will change the rendering.
To get your note highlighting properly you'll need to escape this text with a backslash like so \<WAN-IP>.