clones not looking like mother wtf?

my mother plant is super bushy and covered in close branch nodes....... the cuttings that have been vegging for 3 weeks dont show the same traits at all..... the stems are very elongated with hardly any nodes on them.. the room temp stays between 63-78 always! they have been topped twice and the new shoots just stretch, stretch, stretch instead of forming new nodes. also as an experiment i took a 2nd set of cuttings to compare to the ones vegging and put them under the same light as the mother and fed them the exact same mix as the mother and they too are stretching out..... here are a few pics, the cuttings are growing giant leaves and the mother has tons of smaller tight bushy leaves motherstretched veggingstretched veggingcanopy2nd cut clones on same nutrients and under same light as mother and still stretching


not sure whats causing this any ideas??