First grow issues

I appoligise for starting a new thread just for this problem but I have been confused by the info in other related threads and am worried about my babies.

Hi Im a new grower with 2 blueberry plants under 600W HPS a week appart at week 5 and 4. one plane is thriving and has been moved to a large pot the other plant however is growing very short and thick and hos not show significent growth in a while now. Do you know any possible reasons for this?
Also some bottom leaves on both plants have begun to turn yellow with brown spots and are rather chrispy to the touch. The majority of leaves are also quite droopy yet foliage is thick.
Is this and over watering or nitrogen problem?

I believe if the leaves are crispy that would be from a lack of water.

your plant could be root bound in the smaller cup already. try transplanting then wait about 3-5 days. if growth doesnt speed up then you have a different problem.

reread and noticed that lower leaves are slowly dying. this is normal for a plant of that age. several of the lower fan leaves will turn brown and fall off from the lower sides of the plant as time goes by. you dont have a problem unless it starts happening to stems or upper areas of the plant. or large amounts at once.

take some pics and itll make it a lot easier to see what might be wrong.

Are you vegging your plants under hps?
Fairly normal to see some yellowing around week 5, in flower.
The drooping could be over or under-watering, or too much heat.
Good luck.