There's no way to know if they switched models unless they publicly admit it, because the nature of the tech makes it extremely hard to know why it does any spe

There's no way to know if they switched models unless they publicly admit it, because the nature of the tech makes it extremely hard to know why it does any specific thing at all, let alone to debug it to find out why it didn't do the thing one wanted. ChatGPT discussion here has been totally dominated by this problem from the beginning, but usually it's people raising the bar on what you have to do to get good results from it.