I just transplanted a tomato plant from soil to dwc myself. What I usually do when the roots aren't going down into the bucket is to use one of these siphons to siphon water through the net pot once a day.
This usually take a week or 2 to get things going properly. You want the roots to follow the water.
Your plants must be getting water, if they're growing. Are you using a wick in your buckets?
Just wondering because I have a few plants using wicks this year instead of top feeding and the root system seems to be slower than normal.