When a user signs out or gets signed out of Proton Pass, any auto-lock set by the user is disabled. Please enable auto-lock by default for some interval considerable less than infinity (say 10 minutes) or make the auto-lock interval set by the user persist through sign-outs.
My confidence in Proton Pass was shaken when I became aware that the timeout I had set on my vault had mysteriously disappeared. It helps, but only a little, to find that it happened according to policy.
This request is closely related to a request entitled "Don't void the PIN configuration after logout!", but I want to direct focus to this problem of the vanishing auto-lock interval. The PIN is convenience; the auto-lock is security.