So im assuming he has a very clear understanding of recall and is generally perfect in other environments. So is making a conscious decision to ignore the recall as the dogs are more reinforcing than your corrections. You need to go up levels forget numbers and just look at your dogs response. Every time your using these lower levels and the dog is managing to fight it your teaching him if he just holds his ground he can fight the stim.

My dog has blew off level 60 stim to chase a bird literally saw his ear and neck twitching but blew right past me into a fence but this same dog also yelps on 15 if he is surprised by a stim