Regression is quite normal in a dog's "teenage" phase. Your dog is right in the middle of it. They often need refreshers on their basic obedience skills, push boundaries, and seem less interested in their owners. I think it's the hardest phase of dog ownership because they're getting big and strong and it seems like they should know better, but remember they're still just babies!
Begin to treat him as a little puppy again, with 100% supervision at all times, and crate when you can't supervise. Take him out frequently for potty breaks, reward for going in the correct spot. When you take him out to potty, take him out on leash and be very boring until he goes potty so he can't wander around. It's easy to them to forget that they have to go potty, and then they come inside where its boring and they're going potty before they remember they have to go!
It seems that dogs really don't have complete control of their bladder until they're over 1 year old, so I would keep a close eye on him and restrict his freedom until he's a bit more mature.
Begin to treat him as a little puppy again, with 100% supervision at all times, and crate when you can't supervise. Take him out frequently for potty breaks, reward for going in the correct spot. When you take him out to potty, take him out on leash and be very boring until he goes potty so he can't wander around. It's easy to them to forget that they have to go potty, and then they come inside where its boring and they're going potty before they remember they have to go!
It seems that dogs really don't have complete control of their bladder until they're over 1 year old, so I would keep a close eye on him and restrict his freedom until he's a bit more mature.