Weed will pretty much grow in a cup of sand given the right amount of water and light. I'm thinking you need to check your light spectrum. I had the same issue and that's what it turned out to be. That is - after exhausting all the stuff you've gone through. Get yourself good...
I've gotten white tips and curling from too much ferts but it happened when the plant was only two weeks old. Typically - when older - they can handle a lot more fertilizer.
Unless you have enough space to grow a Kratom 'tree' don't bother. It needs to flower to get any goodness from it. I had a plant for two seasons and it got to be 6ft high but nada effect. So if you can do it outside I'd be interested to see how long it takes to get something out of it.
I've that happen as well. They just delivered a LED TV to my house and wasn't put inside another box. Not sure how they determine how to box things at Amazon. They have a bunch of warehouses so maybe that plays a part.
I picture Attitude like an IKEA store except with Pot seeds displayed - in other words - heaven.
Oh - and the cafeteria sells hash brownies and beer. :)