Some pups are more vocal than others, but whenever you're feeling frustrated with a behaviour your puppy is doing and you don't understand exactly why, chances are your pup is feeling exactly the same.
This is when you can go back to basics and ensure that your pup has had a chance to burn both mental and physical energy. This is oftentimes the most common reason for a pup barking often, which leads to them getting your attention which leads to doing something.
Separation anxiety would be next on the list of reasons, but this one is partly due to the amount of time and space you're taking away from your pup which may be too much for them, but also particularly difficult if they've been left with a lot of mental/physical energy that they don't know what else to do with.