How do I make my Anko paste taste less earthy?

Hello there. So yesterday I got my mom to make anko for me, she had followed the steps except she didn’t used the leftover water from cooking the beans so we used small amounts of normal water to blend it. Then we cooked it with sugar until it starts to thicken. I got to taste it but unfortunately it tasted slightly earthy. I have eaten desserts with anko before and I remembered them tasting a bit like chocolate or something like that without having that weird earthy beany taste.

I also tried adding more sugar and also a bit of lemon juice, but that didn’t made so much of a difference. Are they actually supposed to have that earthy taste or did we just do it wrong? And is there also a way to remove the earthy taste?

Any help would be appreciated