I would suggest going back to the crate. Some dogs just take a little longer to settle down when alone (for some dogs, it never happens!). If your boxer is already crate trained then it is really you who is stigmatizing the crate; he likely is comfortable and fine in there. Many owners who work 8-10 hour days crate their dogs for that period of time with no adverse effect.
You might also look into an exercise pen if you want to grant more freedom but still contain him.
Any practiced behavior is more likely to become habit. So by 'testing it', your dog might be self-learning to chew on furniture and it will be a harder problem to solve the more he does it.
You might also look into an exercise pen if you want to grant more freedom but still contain him.
Any practiced behavior is more likely to become habit. So by 'testing it', your dog might be self-learning to chew on furniture and it will be a harder problem to solve the more he does it.