I just installed Ubuntu 18.04 this morning.
I usually set my browser up when I'm on a new Operating System. So I open Firefox version 62.0.3 and sign in successfully. However, only my ad-blocker and one book mark were synced. No other extension or even my Bookmark Toolbar synced.
I disconnected my account and deleted any remaining info. Then I Purged Firefox and did a reinstall - but this changed nothing.
I would greatly appreciate suggestions.