That's an interesting point.
I've never thought about my philosophy of research - the term itself sounds very "academic" to me and I don't have that "typical UX" background - you know, degree in psychology, jobs in academia then a move to UX. Though I worked for a university, they were autonomous "businesses" so I have more of a commercial view.
Perhaps for that reason, research is a thing I do, but it's not the thing I'm interested in: I'm always trying to answer "what would have to be true to make this a winning idea?"
You've probably guessed from that phrase that my 'philosophy' is rooted in the writings of strategist Roger Martin, and most of my working style comes from Alex Cowan who teaches entrepreneurship at Darden Business School. (Cowan's course combines Design Thinking with Lean UX and mixed Agile approaches.)
In terms of research processes, I just continue to work the way I was taught to work by my previous bosses, both research directors at Cambridge University. Strange now you say it, but in the fourteen years I worked for them, neither mentioned "research philosophy" even once.