Looks like a mix of Ca and micronute defc.'s, but the past troubles shouldn't be causing this so much now,...
-- feeds seem a bit weak, pH OK,... no big sudden shifts you say,... roots now good....
Raise the light up to about 20" if you can, and get the base nutes to about 500 alone, Ca-Mg aside
damage is extensive, no "fixing" it, just hopefully halting progression!