Not sure what I was doing wrong. The cornstarch ratios just seemed off.
The cornstarch mixture for the tofu was thick and clumpy. It would not coat the tofu, so I added a bit more soy sauce and oil. But then when the tofu went into the pan, the coating just slid off and made goop on the bottom.
Used the other sauce for some veggies I cooked separately - it had good flavor, but also needed more water added in order to be smooth and ssuce like.