I'm not sure what to make of an agent's comment on my book

I am a published author but most of my work is academic and I'm trying to move into trade publication. I have a narrative non-fiction manuscript and an agent liked my pitch enough to read the whole thing. I finally got a response after several weeks and the agent had high praise for some aspects of my work. But, ultimately, she told me "the narrative does not lean into its storytelling potential enough to connect to a mainstream audience."

My husband said at least I have something concrete to work on but I don't even know how to start. My usual work is not at all jargon-filled and by all accounts is very accessible. I've even had a reviewer once criticize how accessible my writing is! Where do I go from here?