Are you using synthetic? (I’m assuming you are)
Adjusting to 6.3 is a good plan, that’s where I would start.
I see a N deficiency and the brown spots & leaf edges make me think you have a potassium deficiency. If you’re foliar feeding I guess that rules out calcium & magnesium (I’ve never foliar fed so I’m oblivious to that stuff)
Hope that helps in some way… Plant problems make my brain hurt lol