Desktop client choosing login user

I have to users (admin which manages my NX and private where my files a live). when I first set up NX I installed the Linux desktop client and logged in to the admin. now I’d like to either change the desktop client’s user to the private or have them both logged in simultaneously, while each one has a separate local caching dir.

I tried logging out and in again. it asks me for my server url and then opens a tab in my browser where I should grant access. even if I’m logged in to the private account in the browser, when granting access, NX desktop client keeps logging in to the admin user.
conncted to <my domain> as 'Manager'
manager = admin user

how do you pick which user to log in to in the first place?