Barking when we sit on the sofa

[EyeBetOnSky]

Our puppy has started to bark and nip at us when we sit on the sofa. This only happens in the evenings - the rest of the time she's pretty chilled out. I don't think this is resource guarding as she isn't on the sofa herself - she's on the floor.
In terms of exercise, she gets plenty and sleeps for much of the day. She also has play time, but I try to wind this down in the evenings because if she gets over excited she gets bitey.
Is this just a new phase of puppy witching hour? Does anyone have any experience of it?
I've been trying to ignore her because I don't want to reinforce the behaviour with any kind of attention, but it's so hard. We have an open plan layout so I can't move her to a different room, and she can now easily jump out of her puppy pen. She has a crate but so far I've avoided putting her in there because it feels like a punishment.
My husband is finding it intensely stressful (more so than I am) and I'd like to nip it in the bud if I can.
Any advice would be really gratefully received :)

Is it that she wants to be on the sofa with you?

Our girl absolutely loves cuddles on the sofa. Sometimes she is happy on the floor but only if snuggled up in fleecy blanket

@Totalwasteofpaper It might well be that. She does come on the sofa with us sometimes and once the barking extravaganza is over and she's calmed down we do let her up. But I'm a bit reluctant to reward what looks like a toddler tantrum with a nice cosy sit on the sofa (if you see what I mean!)

It’s the overtired witching hour, our dog used to do this and have crazy zoomies in the evening then suddenly stop and quickly go to sleep, sometimes he didn’t even make it back to his bed and would flop on the floor, bless him.

Keeping them calm and playing mentally rather than physically stimulating games can help but really it’s just a phase you have to ride out. Ours stopped being a little land shark around 5 months.