I see no element "deficiencies"
Those kine things are actually quite rare.

What I do see is root damage from the gnat larvae.
Looks like several "deficiencies," but it's not that elements are lacking.

The plants are trying to grow faster than their damaged roots can support.
That's why the symptoms are confusing.
The up-potting should help with that.

Also noted the sand.
Good move!
You are doing your homework.:thumbsup:
The sand is a pain to deal with so I switched to dryer sheets.
They prevent re-infestation

The new growth looks healthy.
Those bottom leaves show the trouble that you had.
The new growth says that it's been handled.

Don't over-water the 3 gallon pots so the new roots grow fast and they will be fine.

Aloha,
Weeze