I am Patorishasan but I can't sign in with that username. I don't receive the emails sent to reset my password.
I think the draw tool is sensitive to stroke order and stroke direction. Basically, if you don't draw kanji the way that it expects you to, in other words, if you don't write it the way Japanese people who already know how to write the kanji would write them, it might not recognize what you're trying to make. Even if the resulting image looks a lot like the kanji.
I think there are other drawing tools that are less sensitive to these kinds of things. There are also tools like Google's camera recognition thing. You can always use something else and then just use Jisho to check the definition after.
Thanks for the hint about the stroke order. I am actually aware of that but even if it's correct the tool still doesn't always recognize it. I will take your advice and search for the other drawing tools.
Drawing Kanji
No matter how carefully and recognizably I draw a kanji, I often get a sele.ction to choose from that bears no resemblence to what I drew. I then usually have to give up looking for the kanji if I can't find a radical to search for either.