Looks about 2-4 days above ground and not stunted, so something seems fishy for sure.
use size-appropriate pots. potting up does not stunt plants, that's a myth or an outcome for someone that is very bad at the hobby of gardening. Correct irrigation issues, or review porper procedures and reflect on what you've done and if that's a contributing factor. Plant looks too healthy to have been treated poorly for 3 weeks, so i'm not even sure if this is a genuine grow question. shady shit happens on GD.