I would definitely say deficiency of some sort not sure which one,not nute burn though. The tips look fine. And you can see how it’s spreading on the leaves, no tacoing or curling.
Hard to tell from this chart but could also be calcium def, I only have a handful of grows under my belt, but I’ve def learned about nute burn the hard way. Deficiencies are a little bit of guess and play sometimes atleast from my limited experience.