It's lack then, but to know follow
@m0use way. Just wait till run off and collect it into new clean plate, use from your food or new tray if you have, but you will need to drown roots then, it can increase problem even more.
If what you said is truth :
Feed, some leaves will stay damaged, some will recover. If you see any curliness or huge downgrade - give 3-4 only phed water waterings and no feed , start with CalMag after and return to feed schedule.
All the Best !