DWC 400watt semi sealed co2 closet

Lights just came on and to my surprise i noticed 2 plants i had determined to be females due to twin hairs were growing male flowers( im currently around a week into 12/12). Is this common?
So now im left with only 1 viable female snow white ( out of 5 germed - 3 were males and 1 died from stem rot) and my 4 clones of unknown strain.
Pics below
Yellow highlight indicates the males that were there
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First journal part way through grow, this is my 5th grow in closet using a perpetual system. first time running Canna nutes, second run with co2
just got everything re set up following Switched on Gardener Bust - ( scared me shitless)
Quick run through of setup:

Flowering closet -
400w son-t agro, cool tube with 100mm centrifugual, magnetic ballast
Carbon filter with 150mm 2 speed centrifugual
40L Res with 4 outlet airpump variable speed
indoor/outdoor ...