Yea that's common. The models are built on previous versions of themselves. This is something we can fix by injecting into the system prompt "you are X model". We will probably do this as users seem to be suspicious that we are giving them sub-par models. But a nefarious provider could inject that into the system prompt anyways so 🤷♂️ .
Unfortunately it is hard to prove the models we are giving to users. Hopefully something will come along soon that proves such things.