Plants don't become male, don't worry.
Stresses that cause herming the most frequently include erratic photoperiod, high temperature, overuse of bloom blast type supplements, crappy genetics, and overripeness.
Repotting is relatively low stress if you are gentle and can REDUCE stress over time by fixing poor grow conditions.
Flushing isn't all that stressful if you do it right, which is make sure that the pH is correct and that wne you are finished, you feed weakly with a complete fertilizer.