Rice cake help

Hello everyone!
I have been a maangchi fan for a very long time and i love her korean recipes too much! One of my favorite to make on a weekly basis is takboki (sorry i know i am spelling it wrong😳) but i usually buy the rice cakes from my lks . Today however i wanted to make it from scratch… so i made the rice powder and followed maangchi’s recipe to the T. It didnt work though when i added 3/4 of boiling water to the rice it was way too runny and i ended up using 5 cups instead of2!!! Anyone knows why or have suggestions please??
Thank you!!!