Mobile nutrient issues start from bottom up, because it can take the nutrients from the old leaves and use it to make healthy new growth.
Immobile nutrient issues start from the top like this, because the plant can't move it from older leaves, so the "damage" stays in the new growth.
This looks a lot like an iron deficiency. Normally not caused from lack of iron, but rather incorrect ph, which blocks the uptake.
Fix ph and you will most likely fix the problem.