Ajax calls to launch a 200 for one user, a 302 for another.

A user just called and said that a function was not working.
I tried it on my end, everything working.
He prepared a shared screen and noticed that he was receiving a 302 response.
When we opened the request URL in a new tab, the expected data was returned

See attached file 232358

Then, both in Windows, the same browser, the same function, the same input data

What would suddenly cause that to happen?