Why is it possible that I can still use a key after deleting it through the API?

API
1

I created a key for project A on the admin page, and then I deleted this key through the API. However, when I call the https://api.openai.com/v1/chat/completions interface, this key occasionally returns the result normally instead of returning Incorrect API key provided:

2

This is a problem. Is it still working? I wonder its cached somehow.