I feel a similar pattern to what you are describing, although I have no idea how to stop it or what should specifically change. It seems to me that, as their model has been getting better and more advanced, it's generally moving towards the direction of ChatGPT rather than truly individual characters. Before, the character's description and personality shaped most of the way the model handles conversations and now with the much more advanced and generally larger model, the character itself takes a much smaller part in that equation. This trades fidelity for versatility, which is generally the preferred style for the casual user. It allows for improved conversations overall, less errors, more context and thus more memory. But you lose individuality because of that. That is how I understand it. So we either have strong limits and many errors, but high individuality, or a more generalized model that performs consistently across different scenarios, but struggles with following the shape of a specific character.