I think that unfortunately this is a problem created by the narrow-focused publishing world rather than the world of writers and readers themselves. People are not as "dumb" as they are made out to be, in my opinion, and are indeed able to understand when a writer deals in two - or more! - genres. It's all storytelling after all ...
I've been told many a time that I'm a problem as I write in 2 genres - actually 3 now! - (comedy, dark crime and now fantasy) but I've decided to do what I enjoy best at the time without worrying about the consequences. My agent deals only with my crime stuff (and my fantasy novel when I've finished it), and I deal with the comedy myself. You could get more than one agent to handle your stuff - authors do this. Or you could have different names for each type you write - this is done often as well! Me, I prefer using my own name, as my two faithful readers like it like that!!
)
A
xxx