I'm an old hippie, and of course my girls want to go asleep. I ask them how their day was, sing them a lullaby, put them a glass of milk and molasses in the tent and kiss them good night

Don't you too do that????
Of course they don't "need" it in their biology, but they aren't crying out to leave the lights on like strawberries do.
They simply didn't reward me, going up with light time. Perhaps times and strains have changed. That's why I start over with a strain I still know (and hopefully didn't change that much).
Let's put it that way: lights 18/6 doesn't harm them.--- I think.