newstart - that's the problem with OD - the sweet shop / sweet trolley / grass is greener syndrome. Both men and women do it, it's pretty much par for the course unfortunately
This is why you've got to have a thick skin. People will disappear for no good reason, and people don't like giving bad news so you'll often get no explanation why. I've been guilty of letting conversations drift off into nothing, and I've had it done to me too. Sometimes I try and keep a conversation going until it becomes clear that either the woman is just being polite, or she's keen but very boring or just not working for me in some way.
In the past, when I've said to someone I was messaging that 'I don't think we're really gelling, conversationally' I've had vitriolic responses - 'oh, you think you're too good for me, do you? Who the hell do you think you are? You'll never end up with anyone else like me'
To which I thought 'well, that's my point..'
There have been others who I'd thought I'd really made a connection with, either via messaging or in person, and they disappeared, so obviously they hadn't thought the same about me. At that point it's just got to be 'chin up, tits out, move on' and hoping that someone will come along where it's mutual.
The only thing you can console yourself with is that if they treated you flakily, then you're better off without them, because they would have been a flake in real life too.