Ok. Since this is getting nowhere, (I was hoping someone had a quick idea, b'cuz I have no clue) how about filling-out the troubleshooting form, and see if we can notice anything, or connect the dots...?

To me, it appears like something is either blocking the transfer of nutrients to the petiole's, something is going up-n-down the stem chomping at the petiole base (are leaves missing or munched, or do they just fade away?) or the plant has a disease that come with the plant.

Is the base of the petiole have the normal splay where it attaches to the stalk, or has it been munched? Are the attach points on the nodes themselves a 'normal' color, or are there viens of discoloration travelling up or down the stalk?

Would help to know if you added or subtracted any nutrient or additive up to two weeks or so fefore the leaves started jumping-ship.

Did you change or alter the soils between transplants?

Does this happen to every stalk, or is it 'branch-specific'?

How many generations of this particular plant has this clone seen? Perhaps it's just 'tuckerd-out'.

Tiz about all I can think of without going over schedules and growroom conditions. Hopefully, it's not something that can travel from one plant to the next.