[BostonRott]

First, an hour a day ("training overdrive") IS WAY TOO MUCH for any dog, but especially a puppy of 7mos.

Running about sniffing and ignoring you is called avoidance. It usually comes out when a dog is stressed about things (also presents as "zoomies" in class, often seen in agility). I'm guessing that your overly long training sessions stressed him out and that as you go to do those same exercises now in class, all the worry comes back.

As to off-leash, he's clearly not ready for it in the class environment and your instructor should NOT be pushing it! I would continue to work on-lead in increasingly more distracting environments for SHORT periods of time (5-10min MAX) and let him re-learn the enjoyment of obedience, and also gain confidence in you two as a team.

When he's older and more mature, then start working on the off-leash. You could practice at fenced baseball parks when they're empty, or other school ball fields (soccer, football). I personally wouldn't rush the of-leash business.

You need to work on the building the relationship between you two also. Short bursts of quick, fun exercise with a big reward at the end. Finish your training while he's still really up and excited, leave him wanting more. If he can do 5 reps well, finish at 3.

I have no issue with group classes, they have their time and place, especially for teaching a dog to work around other dogs/people and work through distraction. I know that private lessons can be expensive, perhaps you could split an hour with someone in your class, and each keep your dog put away while the other is working (to give the atmosphere of the private lesson).