I just tried it. I have example.com in my history, and typed "exam". Example.com is the second thing firefox suggests. Before it, is a duckduckgo image search result page for the query "botanist", with an image titled "Young Botanist Examines The Plants In A Greenhouse Stock Photo". Firefox is picking up the "exam" in "Examines" and puts that result before example.com.
I don't really care which is first, I just want one or the other to be consistently first.