Sign-in to Driver Update even though already logged in to N360

I have 2 machines running N360, with Driver Update active.

On Machine 1 - with N360 running, I click on the "Driver Update" button, and the update function starts

On Machine 2 - with N360 running, I click on the "Driver Update" button and the update function requires me to sign-in again

What gives... with both machines running the same licensed version of N360, why do they behave differently?

And how can I fix this?>