Is my marijuana plant okay?

Hey so I should just look at the new growth to determine how the plant is doing right?
A fellow grower is in need of some advice:

One of my plants are doing really bad… for some reason, they are all in the same environment, same nutes, same light… Don’t understand but one of my healthy plants is showing some mild yellowing on some of the leaves… not the bottom ones, which may indicate N deficiency but like the 3rd from the bottom?

The ones right at the bottom seem to have no problems…I guess it’s hard for you to know without pictures… but I just want to know like, if something went wrong with my plant, and if I correct the issue it can still grow fine right?

Or are some damages permanent? (not how the leaf looks like but overall plant growth?)

Thanks!

PLease fill out this support ticket, designed to help us make a more informed decision, as to why you are having issues.