if you have been feeding regularly, back off for a while.
autos are more sensitive than photos, so if you have fed regularly, it is caused by overfeeding for sure as opposed to a deficiency. i am not familiar with that brand and whether you shoudl cut their instructed concentrations or not.
that's been progressing for a while, so it's not new.
Is that the same plant in 2nd? looks like beginning of Ca or water dripped on it. check the bio bzz labels, ensure it has a Ca component somehwere. Could be lockout caused = k/p-tox can cause Ca/Mg-def, but you'd see other signs with it.
use up what you got but ponder switchign fert brands. A good feed doesn't run into these problems.