I have published eight volumes of short stories, and now that I'm going through Draft2Digital, I have an obvious titling problem.

I called the series "The Screw Turns" and each publication was just the series name and volume number. That worked fine on KDP and Kobo, but in D2D, the reader will see the title repeated twice.

With my novels, this doesn't happen bc each novel in a series has a unique name. E.g "The Book of Joy" in the "Princess of Darkness" series.

So should I name each volume?