Dupes randomly sleep on floor

It's either bio or skills, but one of those will tell you about her positive and negative traits; check to see if she is narcoleptic as that means she can and will fall asleep anywhere at any time.

I hope this helps!

not narcoleptic, dupes hit night time and one decided right there on the floor where they were was fine

Did you check their stamina? Some dupes get off schedule for whatever reason (maybe they're taking care of a necessity before they head to bed, like using the bathroom or eating), then when their stamina hits 0 because they're not sleeping correctly they'll drop right there instead of walking to bed.

Edited August 3, 2018 by Geschinta

I've experienced this issue with freshly printed dupes for the "first sleep" in an unasinged cot; and with a manually assigned cot for the first cycle. After the first cycle of sleeping on the floor the dupe goes to bed properly every cycle after.