Assuming they're not just reading it from a checklist & tuning out when you start talking - they're looking for a story where you had a problematic relationship with a coworker or coworkers, but managed to make it work. Ideally over a longer period of time, and not "Bob stole my lunch out of the fridge one day". For reasons similar to what you said I've found a lot of people don't have very good stories along these lines, and because of that this question is less useful than people like to think. And on top of that, most candidates are terrified of saying anything that makes them look like the ahole in those situations. So if their answer sounds pretty milquetoast who is to say if they're being careful or just don't have good stories.
I have a story I use now. It involved a coworker with whom I had an oil vs water relationship for a couple of years. In retrospect I could have gone about it all a lot better than I did in the moment, although that was true for both of us. I don't have the perfect "And then I solved everything" punchline to my story, they were eventually let go. But, my journey during it all was critical to my own development. And that started me down a leadership path, changing the course of my career. So I talk about my lessons learned, things I wish I'd have done differently in retrospect, etc. I'm not painting a perfect picture of myself, but I do display introspection, personal development, willingness to take different approaches to resolve an issue, etc.
The oil vs water thing resonates. Given that tenures are relatively short these days (1-2 years), it's pretty easy to just wait it out -- especially if the other person has issues with other people too.
I do feel like too many of my examples (for this whole class of questions) are times I could've handled better (though I didn't handle them catastrophically by any means), that ultimately shaped how I think about such things going forwards (after a fair amount of introspection)). But I often seem to lack the examples of a subsequent situation where I put that into practice (pandemic meant I basically took a holding-pattern role for a couple of years).
One would think that introspection, recognition of ones own mistakes and being receptive to feedback would be a massive pro; but lately that hasn't been my experience when interviewing.
I have a story I use now. It involved a coworker with whom I had an oil vs water relationship for a couple of years. In retrospect I could have gone about it all a lot better than I did in the moment, although that was true for both of us. I don't have the perfect "And then I solved everything" punchline to my story, they were eventually let go. But, my journey during it all was critical to my own development. And that started me down a leadership path, changing the course of my career. So I talk about my lessons learned, things I wish I'd have done differently in retrospect, etc. I'm not painting a perfect picture of myself, but I do display introspection, personal development, willingness to take different approaches to resolve an issue, etc.