Potty training new puppy in new apartment

I have a 6 month old German Shepard mix. Adopted him about 2 months ago. We were living in a house for about 6 weeks until we moved into a new apartment. We’ve been in the new place for about a week and a half. He was very well potty trained in the house. The first couple of days, anytime he peed in the house I ran him to the back door and let him out. He caught on pretty quickly and only had 2-3 accidents after the first couple of days.

In the new apartment, it seems he doesn’t know how to tell me when he’s gotta go. He’s having accidents everyday (sometimes multiple per day). But he’s not squatting down and letting everything go. I’ll be doing something like cooking dinner while he’s doing his own thing. Then I’ll notice a small line of pee dribbled through the rug and then rush him out and he pees immediately. And based on some other behavior, I think he knows he’s not supposed to pee inside but he doesn’t know how to tell me when he’s gotta go. Seems like potty training basics but a slightly different situation because of the move. What should I do? How can I teach him to talk to me in the new apartment?