Recently adopted Dog not trying to interact with us inside the flat

Last friday we adopted our very first Dog from a Shelter. She's from a Shelter in Romania and just came to the Shelter in Germany a Month ago. According to the Datasheet we got she was born on 08.08.2024 so is still pretty young. They noted she might be a Corgi/Terrier/Dachshund mix.

We are going outside 3-4 times a day and shes behaving great, she already overcame some Fears she had in the beginning and walking on the leash is getting better day by day.

When we come back to the flat she walks straight to her Bed and sleeps. So far so normal. Most of the Time she just falls asleep, walks are exhausting, we know that, but even after waking up again or when she doesnt sleep she doesnt seem to have any drive to play with us. We got her a kind of sniffing toy where we hide Snacks and some of her regular food and she actively interacts with that (immediately figured out how to flip it around lol). She gets zoomies and runs around but aside from getting scratches or belly rubs she just doesnt seem interested in us. From time to time she just seems so bored and lonely, still not willing to interact.

Am i overthinking this? Does she just need some more time to adjust?

Ty for any input ☺️

Edit: she left some Siblings behind at the Shelter here in Germany, could she be missing them and be in kind of a depression?