Change in behaviour at bedtime

Hello everyone!

I have a question because my dog (a 2-year-old miniature dachshund) has recently started behaving differently at bedtime.

Normally, I read or watch TV with him on the sofa (he’s usually calm when settling down for the night), I take him out to pee and so on, he comes back to the sofa and sleeps there. End of story.

Now, there’s been no change to the routine, but it often happens that 2–5 minutes after I’ve left the living room, he whines and goes and stands behind the living room door.

If I open the door, he wants to follow me.

Sometimes it’s enough just to put him back on the sofa once with a “now it’s time to sleep”, but yesterday it happened about five times, so I’m not quite sure what to do anymore.

Has anyone else experienced this? Do you know what might be causing it? Any advice on how to get back to how things were before?

(I should point out that we’re very close, we’re together most of the time, but I do often go out for several hours during the day and that goes fine – no separation anxiety)

Thanks!