Different routine, but also likely that she is over bonded with you and not so much with your other half, so when you go, she misses you terribly, but because he may be more 'offhand' with her and matter of fact, it is no big deal when he goes.
If it could possibly be this, then you need to not give her so much attention, even not talking to her for half an hour before bedtime,so that when you go it is more of a relief that you have gone, than dispair!!
It is also telling that you slept downstairs with her, I understand your reasons, I am all for an easy life too, but would your hubby have done that?
Kate