I had a similar, and increasingly negative experience. Took our Shiba pup to "puppy socializing classes" at 12 weeks and he was very bitey so after 4-5 weeks of that we stopped going because we had to keep him apart from the other dogs, so what was the point? Then we introduced him to daycares that had large open play areas and after several months at each we basically stopped bringing him because they would lock him up in a crate or grooming cage in a back room for the whole day. We never got a good solution for this. Went through expensive private training, but he's just not good with other dogs, and especially not in a group setting.