Did the edge curl during the heat-treatment or after you started grinding again? Either way, I think the problem is it got too thin. I that find if the grind isn't uniform in thickness prior to quenching, the thinner parts tend to buckle a bit. I haven't seen waves like that develop during finish grinding yet, but right at the edge you'll sometimes get some metal that's paper thin and starts to ripple. Maybe you've almost ground through the blade near the center?

Regardless, that's a fantastic first effort. Heck, it would be a good 10th effort.

Keep at it!
Josh