A question from a fellow grower:
I transplanted them into bigger pots with local soil and potting soil mixed.
They are outside, and get full sun, but they don’t appear to be growing any. They have had their second leaves now for over a week, but are still not much more than sprouts.
I keep them watered, but it’s just like they’re stuck.

When you transplant; You will not see any growth until the plants re-root. You re potted that little thing way to soon. I advise you consider being more patient in your growing. You should never transplant until the plant has grown full roots, and fill the original pot. Short of being root bound of course.
Wait a few days. Keep the area around the plant moist, but not too wet. Good Luck.