The work seems appropriate for him, and the environment is also satisfactory.
Did you discuss this specifically with your DS when he said that no one was helping him (ask him about the work)? Maybe, he is just satisfied with the work content and not really enthused about it because he is capable of much more? Could that be the issue?
As for the recess - it is fine to go off alone and play by himself if he wants to because he may be trying to decompress and may need that alone time away from the noise and movement and busyness of the other kids.
