Considering this is from academia, there's a chance there were limitations on the available models. My research group accesses OpenAI models via Azure, and until recently (last week) the latest model was GPT 5. We just got 5.4.
The university doesn't « ban » using the OpenAI APIs directly. It's a question of funding. If you want to use OpenAI, you usually use your own account and ask the university for a refund later, where you justify your usage. It's easier for the university if you use their pre-approved Azure endpoint instead, though you'll still need approval if you're going to spend a significant amount of money.