@Craig Parsons a few thoughts on this. As an agent who specializes in investors.
Just right off the bat, I don't see anything you did explicitly wrong. So you may just have had some bad luck, or perhaps it's some sort of local custom you violated. Or maybe there was something unexpressed. Like something you may not have realized you said in that fifteen minutes of phone conversation that caused the agent to split. I don't know.
All that said, however, there are a few points that have been made that do carry some weight. The commission discussion certainly is one. If I'm not able to make a certain commission amount on a deal, I will charge an adjustment to my client. It can be substantial. That is to say, transactions under $100,000 almost always require an adjustment. Now, of course, an agent should discuss that with you and I presume you'd be understanding. But it's still part of an issue of the value of my time and effort.
For example, I have no shortage of clients who come with $20,000 and want me to make them a BRRRRillionaire. Essentially people who are just not serious (and they always think they are) or realistic about the market. I used to waste a lot of time on these buyers. Along a similar line, they're often asking for 90%+ LTV owner-financed deals, as if they're the only ones who'd want them. And it may be more common in your market, but a lot of owners where I am simply decline it. Other people say "well, I'd rather not go conventional, but I'm guessing you probably know of some private lenders who will do 30 year fixed for 0 down".
It's insulting to agents because they're basically asking us to "make" the deal for them. Usually because they can't do it otherwise. If it was within my power to "make" such a deal, I'd be giving it to one of my existing clients or keeping it myself. And to be clear, sometimes it is within my power to do that. But again, that's a privilege.
I don't have all the information, and I don't see what you did wrong here. But agents waste tons of time on tire-kickers who aren't serious. So we do have to be very selective about who we give our time to.