how to reference a bind variable in html expression?

Reference to a bind variable like

&location.

but sometime it works and sometime not work.

Why?

Here is the complete HTML Expression:

<ul style="list-style-type: none; text-align: left;" >
<li><div><span class="u-bold"></span> &category.</div></li>
<li><div>&location.</div></li>
</ul>