Try another flush and if you still can't get that perfect 6-7 pH add pH-down (foundin pet stores, usually used to lower pH in aquarium water, it's very efficient, using organic acids).
Your K deficit was clearly caused because the K was locked out due to pH. Lower the pH and you'll be in the green (many puns intended).
PS: don't overfeed her now with Super Bloom. Because all that K (and probably some other nutes) was locked out, there's a lot of it already in the soil. Adding too much now can kill your plant. Add 1/2 - 3/4 of your usual nute concentration for another week or so or until you notice total recovery from the deficit.