Most fry are inactive unless they're "hunting" or startled. Most of my fry remain like this until they are 1cm (specially when they have a full belly).
3 days after free swimming .... try this: vibrate a small chopstick or your finger on the water surface. They should slowly swim towards the stick .... you could also use this method to feed them once most are there. They will stop approaching vibrating stick when they reach 3 - 5 mm.
In nature, dad would take some food, vibrate his pectorals rapidly - calling his fry. Then he would release food debris for his fry to eat. Sometimes he would also mouth them for a short time.... not sure what's he doing.