Need help: multiple request throttling

I have an issue in the CraftCMS back office when I try to export all entries.

When I try to export all the entries in expanded mode

it takes ~1min but every minute the back office send another request bundle-office/actions/users/session-info,

when this second request is sent, the export request is timing out and return a 502 Bad Gateway.

Does anyone know how craft / nginx handle those requests and how could I fix this issue ?

Thanks