Sounds like the new one was trained on senior engineer’s with ego’s, maybe even grey beard’s. Majority of the training data is low quality, so sounds like “yes, you’re right! It works! I commented out unit test’s and now all test’s pass!”, while the new one is a passive-aggressive “if you know better and you talk to me like that, fuck you do it yourself”, or simply turning around and walking away because they don’t need take the abuse anymore.