A week is not nearly enough time to determine if this is a real problem or a stressor because of the new digs.
Keep an eye on your new addition (kudos to you for adopting) and go on frequent walks for the time being, until at leaast a couple of months go by. Make certain you get out the entire parade when the pp occurs outside, JRTs are very smart - my guess if you are on top things is in 2 weeks you should see a dramatic improvement. If not repost.
Good luck

I love it! "Poopy Parade."

I have a poop party when my Lucy pees/poops on command. My neighbors must think I'm nuts. "Yay! Good girl! Yay!" Lucy thinks I'm nuts.

Be patient. I agree w/ Mazer.

Yes, JRTs are a very intelligent breed, albeit a little headstrong. This little fellow has been through a lot of confusing shuffling back and forth and perhaps a traumatic separation from its previous family. It's very normal to go off a potty routine even if they were perfectly trained at some point in time. My iggy didn't have potty issues, but had such a severe separation anxiety he would self mutilate even if I stepped outside the door without him for a few minutes. It resolved within a month to an acceptable point and after a few months he is quite fine when left for a few hours on his own. Be patient.

I adopted a Jack Russel from the pound 10 years ago. She was 18 months at the time and had the tendency to pee when she got real excited and so, was discarded.

She has been my best friend for these past ten years and I wouldn't have missed any of it. For the first few years, whenever we would come and go we would ignore her and not touch her to avoid the "squat".
Eventually she grew out of it totally, except, last year when we went on vacation for a week, she did it when we got home.
We had full time house sitters, btw.

She is smart...ohh, so smart. I feel like she understands everything only that we speak different languages.
She certainly has mastered my body language and habits.

But for your info, the first couple months, she was NOTHING like what she was to become. She was afraid of everything for a long time, and so timid.

I remember trying to house train her the first few days and a friend told me to develop my own language with her and to use the phrase "Do Your Business" and make a party over each outside tinkle and poop.
But I was frustrated and she didn't seem to understand "Do Your Business" at all.
So, one day I said "Tinkle" and she went down immediately! She knew THAT word!

But eventually we learned each other's language and became friends.