https://support.mozilla.org/en-US/kb/using-master-password-sync Passwords will not sync to Firefox for Android if a Master Password is enabled.

As far as removing your Master Password on desktop Firefox, that is the same as resetting your Master Password. https://support.mozilla.org/en-US/kb/reset-your-master-password-if-you-forgot-it Warning: Resetting your master password will remove all of your saved usernames and passwords.

I had a master password established prior to migrating to Firefox for Android, and all of my logins have successfully showed up in Firefox for Android. My problem is that they disappeared from my desktop Firefox.

Hi, If you have a copy of your data on a mobile version of Firefox, please follow these instructions to connect it to Firefox Sync to copy your data.

• https://support.mozilla.org/en-US/kb/how-do-i-set-sync-my-computer#w_connect-additional-devices-to-sync_

Please let us know if this solved your issue or if need further assistance.