How to handle internship experience with flawed model in interviews

Hi everyone, I did a summer internship this year at a bank. My final project was to update and revise an internal model that had been built several years ago. As I worked on it, I realized the model itself had some flaws — the outputs didn’t align with what was reported, which made it hard for me to proceed with the project as originally scoped.

What really surprised me was that this model had been used regularly for a long time without anyone raising questions about its outcome. That experience made me much much less passionate about the work and the position.

My question is: is this something I could bring up in full-time interviews, maybe explaining why I do not get the return and why do I still want to recruit elsewhere? Or would that risk breaking confidentiality or make me come across as negative about my previous team?