There can be a lot more differences at work here, other than taper vs non-taper. Are you using the same stem and bars (or very similar ones) between the 2 bikes? Do you have a similar distance between the top headset bearing and the stem? Is the distance between the top and bottom headset bearings similar?
A noodle fork tube combined with a short bearing span and a long entension above the top bearing will feel even more noodle-y. Add a long stem, and you’re steering through molasses.