5 autos, one is yellowing on the top also curling upwards edges

5 autos 25 days plus minus, one is yellowing on the top also curling upwards edges, the others are all green no yellowing
same soil same water , soil ph 7 but for all of them and just that one is yellowing on top

its hard to say

that one might be nute sensitive and the others will be fine
or that plant might be nute sensitive and therefore the first to show an advancing issue

for what its worth
the leaf curling like a taco or canoe

that's often the first signs of mild Magnesium def (add Epsom salt)

yellowing on the new growth is usually a sign of micro def... 1st likely is iron

have they been getting any fertilizers or just water?

so if they've been in the soil for a few weeks without nutes they made need some food and this could be the first one to show

on the other hand nute burn toxicity can look a lot like many other things.... if you haven't fed thm any fertilizer as of yet then you can rule out nute tox. and air on the side of adding fertilizer