Hello shiloh , I affraid that when on the "night" period of the 12/12 cycle the plant has to be kept in the dark without any interuptions of light at all.
Honestly any of the growers on here will tell you the same, that interuptions to the dark period will seriously effect flowering and growth of the plant.

The only thing I can think of is to have the closet door closed when the light in the room is on or prehaps use a curtain to sheild the plant from the light



love mand xxx