I have a pen name picked out, and I have a project that will be the first one I ever query. I just did a preliminary search to see if my pen name and my MS title are already out there. There is a published author with both a similar name and a similar title. Think: Janet Reid’s sci-fi book Query Shark vs M.L. Janet’s YA book Shark for Queries. I saw a kerfuffle online about a similar issue between authors of the same genre, and it has me wondering: How close is too close? Where is the boundary between “I also thought of this myself” and “I’m trying to ride your coattails for recognition?” Is genre a big enough difference? Will the agents being queried see those similarities and think I’m unoriginal? Which is more important: changing the title or the pen name? Many thanks for any of your time!
Notice that you saw a kerfuffle among authors, not agents.
This is not something to worry about at the query stage.
Nothing is public yet.
If your name is Lee Child and your book is called Reacher Goes Wild, you're going to get a name and title change pretty quickly.
We'll talk about this at the representation offer portion of the year's entertainment.
I'm not going to worry about your name or your title until I have a real reason to do so.
I'm telling you it doesn't matter but if you're absolutely convinced I'm wrong, change your title before your change your chosen pen name. A publisher has final say on the title so it could change between acquisition and publication, but I've never had a publisher ask for a name change because it was too similar to someone else's. I'm sure there are instances of that but my guess is they are rare.