AsNoriuanswered grow question 2 years ago thought its aftermath of overfeed, but you stopped on time, so she recovers .. bla bla bla, but honestly - most i think its wind damage, second you underwater her and she gets big temps or too intense light. Calcium and good watering regime is what she needs to cope with it.
calmag feed, very light for few waterings in a row will bring her back. 0.25-0.5 ml/L