Explain the problem.
pandoc -f jira -t html jira.txt -o test.html

with the following jira.txt:

{panel:title=This is the title|titleBGColor=#cccccc|bgColor=#eeeeee}
Panel content
{panel}

produces the following output:

<div class="panel" title="This is the title" data-titleBGColor="#cccccc"
data-bgColor="#eeeeee">
<p>Panel content</p>
</div>

This does not look too bad at first glance, but while the panel's title will be formatted as a kind of headline by Jira, the div's title attribute in HTML is not visible at all by default.

This is a significant different in presentation, and on the surface, the panel's title text got "lost" during conversion.

Pandoc version?
pandoc 3.1.1
Features: +server +lua
Scripting engine: Lua 5.4

Debian GNU/Linux