This is a question a lot of authors agonise over and it ultimately boils down to what you want.
However, first, I urge you to make an informed choice.
If you write cross genre, it’s recently come to my attention, whether you traditionally publish or you’re an Indie, you need to consider the impact of Amazon’s algorithms and how they affect your sales.
Most authors loathe marketing. It’s a fact. Learning how Amazon works and promotes your work, is a ticket to minimal marketing. So make Amazon work for you and don’t confuse it. Using the same name if you write cross genres is guaranteed to confuse Amazon.
Take me for example, I currently have a memoir and I’ll release fantasy in the future. Now, my fantasy will most likely be the stronger seller (fiction is more popular than memoirs, so it stands to reason) then it may appear in my memoir’s ‘Also boughts’ (on Amazon) if I used the same name.
Amazon algorithm’s can’t differentiate between a fantasy and a memoir. A browsing memoir reader will be confused to see a fantasy on a memoir page. What do you think happens next?
What happens is not Amazon’s fault. The reason it happens? An author uses the same name.
Just throwing another initial into your name on a book in one of your genres (different to other genres), can help the loathed marketing chore. Different names is something Amazon algorithms can differentiate between. ‘Also boughts’ are a free form of Amazon marketing, so it’s worth making them work for you.
When deciding one name or a different name consider the impact of Amazon’s algorithm for your ‘Also boughts’ if you write cross genre.
If you want to see what inspired me to write this post, watch this (starting around the 15 minute mark, although the entire video is time well spent). Many thanks to Joanna Penn and David Gaughran for educating me.