Can't escape special characters in Custom Breadcrumbs

I want to create a breadcrumb menu that (in some contexts) takes the user to a specific tab under a set of quicktabs. One example of a URL I need to use as a breadcrumb path is this:

about-us-new?qt-get_involved=1

(This would take you directly to the second tab on the "Get Involved" page of our website.)

I installed Custom Breadcrumbs, and I've been searching online like crazy and trying many things in the code, but the href always ends up like this:

Get Involved →

The question mark and equal sign are messing me up, and all efforts to use html_entity_decode and similar functions don't seem to work...those characters are still being translated into HTML escape characters.

Any suggestions?

Thanks!