Reinforcers AKA Rewards are not created equal.
When you discover things your dogs like, write down specifics. If they like to be pet in a certain spot or enjoy time running off leash take note. What about treats? What do they drool over? Yes sure some dogs will work for kibble, but others want high value, such as cheese, hot dogs or freeze dried raw meat. Maybe your dog likes variety. Knowing what your dogs LOVES will help you motivate them when you’re training, as well as help keep them focused on you.
If they are not focusing on you, you can go back to the list you made and either select a more valuable reinforcer or decrease distractions. Rank each dog’s list of reinforcers by value, remembering that what reinforces one dog won’t necessarily work for another. Maybe your dog enjoys tug verses food.