SOLVED: The macro that I thought was malfunctioning was actually not running because I had placed it in a group that worked only when the Finder was the frontmost application. So, it wasn't running when Chrome, Safari, etc. was the frontmost application.
I had copied the url from the first tab for some other reason, manually. So, when I triggered the macro, thinking it actually ran, it didn't.
It works now that I moved it to a group that works in all applications.