Before starting a feminized run I spend an evening inside the tent with the room lights on and the tent lights off, looking for pinholes and zipper gaps. A tiny leak during the dark period is one of the most common triggers for intersex flowers, and it is entirely preventable. The environmental checklist on
https://queenfeminizedseeds.com
puts this step at the top for good reason, alongside checking timers and fan controllers. Ten minutes of inspection saves a lot of second guessing later in flower.