The same thing happened to me, I thought this was disabled in the present version. So I'm waiting for the new update to see if that is the case
Well, I just quit trying her route for now. I ended up maxing Kimberly out, by going in the morning, but never saw the Stay the Night event.
Also, maxing out Sydney doesn't have anything to do with Kimberly. All it does is letting you in the house and a scene with Sydney in the closet when playing hide and seek. (Which never happens as well, since it's bugged. It teleports you back outside and you can't get in anymore)
Another bug I have is with Ms Amos. Her stay the night event happens, but she keeps spamming my frickin phone every night asking me to go over. Every night! There are more than 50 messages from her already. :coldsweat:
I like the game but the bugs are annoying.