Did you clear your private data right after syncing?

If so, 'Clear Private Data' clears all of your private data, including saved passwords. If you're syncing passwords, and you delete them all, the deletions will propagate to other devices.

No, I did not clear my private data. It was the initial sync process of my Firefox on the iPhone. Please restore my data from 13.11.2015 06:00 UTC or before.

Some questions for you:

Where are your stored credentials gone? On the iOS device or on your Windows device?

What did you do to determine that?

Did you upgrade Firefox on your desktop recently?

Is there a file named "logins.json" in your profile directory?

From a technical perspective (I built the Sync client for iOS): Firefox for iOS never sends remote wipe commands, and the only way it can mark a password record as deleted is via Clear Private Data.

My credentials are gone on all my systems (iOS, Windows, Linux) after setting up Firefox Sync on my iOS. On my desktops my firefoxes were updated when then lastest update came out. There is such a file but it has the present time stamp.

Did you sign out of Sync and back in again on the iOS device at any point?

Did you save any logins on the iOS device before setting up Sync?

Do you see any entries in Saved Logins on your desktops?

Thanks for your patience.

By the way, I'm tracking your report here:

https://bugzilla.mozilla.org/show_bug.cgi?id=1226026

If you're available to investigate, your time would be appreciated.