I need a QQ ba wan (Taiwanese meatball) recipe?

I've looked for recipes for this delicious Taiwanese favorite dish and found 3 recipes online. All of them call for different measurements of rice floor and sweet potato flour, but I can't get the dough (skin) to come out chewy or what us Taiwanese call QQ. I don't know what I'm doing wrong. I've tried stirring it for over 1 hour in one direction and increased the sweet potato flour as my mom believes that the "QQ" part. There has to be a secret to this recipe as most of the restaurants I've tried don't get it right either. Any expertise will be appreciated.