What's wrong? Canoe can be one of many things... soil might be a bit hot? light could be too close? that last one is easy to eliminate it if familiar with it. if light related -- growth will stack up ontop of itself with veritually no internode spacing... another easy way to eliminate that cause. This is less likely, so geting it out of the way.
I see you are in coco coir? So, it does need fertilizer each time, but only if you fully saturate with 20% runoff to ensure no buildup occurs. Also, the first 2 weeks or so are powered by the seed anyway. The problem with a big pot and a small plant is doing this without overwatering... in coco coir you shouldn't have to worry.. get the how substrate evenly saturated with 20% runoff.. each time.. wait for a little dry on top before next. (not quite as dry as soil on top, but it should change color a bit).
be prepared to wait many days before watering again... culture shock if not doing that before. this avoids algea growth up top too.