No, the password of the Firefox Account you use for Sync is only used for this Firefox Account. This Firefox Account password is used to encrypt your personal data locally before it is uploaded to the Sync server. The primary/master password is used to provide extra security in the Lockwise Password Manager and this master password never leaves your computer. Each device can have its own MP, but each device needs to use the current password of the Sync account to connect to this account. Note that resetting the password of the Firefox Account will wipe (remove) all data stored on the Sync server as only the original Sync password can decrypt data on the Sync server. *https://support.mozilla.org/en-US/kb/ive-lost-my-firefox-sync-account-information *https://support.mozilla.org/en-US/kb/use-master-password-protect-stored-logins