Hey
I've made the small mod Better Lydia AI (old name Chair for Lydia).
So I gave Lydia the sleep ai package... but when I ask her to follow me, she will go back to sleep.
It's not "game breaking" because she follows me when I've fast traveled or if I leave the town.

So my question is... why does she go back to sleep? and how can I fix it?

Sounds like the Sleep package is taking precidence over the follow package. If its in her stack, place the follow above it. Or give it a condition not to run when she is supposed to follow. Theres probably a bool variable on the follower scripts you can address.

Thanks for your help... but I can't anything.

You also may want to check to see if the "Must Complete" flag is unchecked.

Yeah, it's unchecked.

You should add a conditional on the sleep package that makes sure she's not following. A simple way is to check if she is (not) in the CurrentFollowerFaction, eg

GetFactionRank CurrentFollowerFaction < 0

In the worst case, you should do this on any packages that you are adding that are meant for when she is not following the player. I am surprised though that the DialogueFollowerQuest packages are not overriding her default behaviour when she is following.

If I may interject: I'm trying to assign a sleep package to Lydia but when I do, she sleeps the first night then stands in one place for hours every night afterwards despite two different beds in the house. Did you run into this problem?