My thoughts are that he doesn't want to be somebody's meal ticket, and to step in and take the place of a man who does nothing to support his child.
Perhaps he doesn't really want a relationship with a woman with children at all? Did you mention that in your bio or did he only find out after chatting with you?
It's perfectly okay to not want to take things further upon finding out someone already has kids. It changes things profoundly. Maybe he'd be okay if you didn't live with your child for whatever reason, or if you had 50% of your time to yourself, but he doesn't want to come into a relationship where there is always going to be three of you from the beginning and very little chance for plenty of time just the two of you? Perhaps he wants to be able to travel or go out on dates that don't involve just sitting in your house because you have no childcare or no spare money?
There's no point in wasting your time getting so far down the road only to see him back off after a few months because of your parenting responsibilities and you say 'but you knew I had a child all along. Why waste my time?'
This way, he isn't wasting your time. It's a bit like asking someone early on whether they want marriage and kids or not. If you want them and they categorically don't, just don't invest any more time in them. Not even two dates. It's not worth the risk that you fall for one another then spend the next few years both feeling resentful because you want different things from life.
You may find these questions too intrusive or blunt but that's because I think you know your being a mum might put some men off and they'd prefer someone with no 'baggage'. You want to let them fall for you first, just see the single woman and not the mother, then hope they'll come round to the fact you have a child later because they've already decided they really like you.
Whereas I think it's perfectly okay to have boundaries and expectations from the very beginning and to stick to your guns about what you want or don't want from a potential partner.