Can't highlight Drop Down List in some case Rated 5 out of 5 stars

I love this addon.
The 2.6.2 version can not highlight the content of Drop Down Menu, but 2.5.0 version can.
Example, the contents under the menu " Extensions | Personas | Theme …" in this page.

This review is for a previous version of the add-on ( 

Before version 2.6.0, SearchWP used an own searcher on highlighting, and the native finder on single term searching (by clicking buttons). Those searchers where inconsistent with each other in too many cases.
Since version 2.6.0 we use the native finder on highlighting too.

See Firefox related bug:

Even if we can reconsider to highlight in listboxes/option lists, it could be easier to create a separate extension to enhance similar form controls.