Cookies use for AJAX calls expire but not the main cookie.

When we have a browser window logged into teamcity UI and after performing various user operations on the UI,
we are faced with an error where when you go to a build overview page you get an empty list of builds.
According to the cookie dialog (F12 -> Storage -> Cookies) the cookie didn't expire, but the ajax call return unauthorized (Error 400).

Clearing cookies causes a re-auth and things work again.

We have an NGINX reverse proxy in front of teamcity which also does HTTPS termination.
Authentication for TeamCity is using AzureAD

On NGINX we have configured in the config:

large_client_header_buffers 4 32k;

but this doesn't seem to fix the issue. Any pointers would be appreciated.