You need to close Firefox with all windows you want to restore still open. Otherwise only the last closed window is restored.

Use one of these to close Firefox if you are currently doing that by clicking the close X on the Firefox title bar.

• "3-bar" menu button -> Exit (Power button)
• Windows: File -> Exit
• Mac: Firefox -> Quit Firefox
• Linux: File -> Quit

As much as I hate to hear this, I started to think that was the case.

So is there any way to access the synced device from before? It's in a list of Apps and Devices, two spaces down from the current one. It would still have all my tabs saved, I just need to get to it.

If your Firefox restored your previous session, you may find "Recently Closed Windows" and "Recently Closed Tabs" on the History menu. Either:

• (menu bar -- tap Alt to activate) History
• "Library" toolbar button > History
• History toolbar button (optional -- Customize Firefox controls, buttons and toolbars)

Regarding Sync, I think it is running in real time, so that may have been updated from what's happening locally.

on the other device do this :

• https://support.mozilla.org/en-US/kb/export-firefox-bookmarks-to-backup-or-transfer
• https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Then let it sync and then restore it using the above then sync it back again. Yes will loose current session as above say.

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