The proxy password changes because it is a one-time key, tied to a single work session - not a permanent login. Once that session ends, the old key is useless.
When an assistant starts a Grant, SyncNow issues a fresh password for the local proxy on 127.0.0.1. The assistant uses it for that session only. If the session ends, expires, or is revoked, the key is rotated, so a leaked or stale value cannot be replayed later to reach your project.
What this protects
It limits the damage if anything ever leaks. Even in the worst case, a captured proxy key is short-lived and local; it is never your real FTP password, which stays in the cloud vault. The key also rotates if SyncNow revokes a session after rule violations, so trust can be withdrawn instantly.
SyncNow