Back in the early days of Sync feature in Firefox, we had option to force override data on Sync servers depending on your needs. You could merge the data, force currently used client to be overridden by the server data or current client overriding the server data.
Several updates later, and we have absolutely NO control over sync data. It just syncs up whatever way it feels like it and frankly, in most cases it’s not the way you want it. Things often go bad with Add-ons if you are testing them and you’re adding and removing them before other clients under your sync account receive data from Sync service.
However, I found a way to at least partially regain control in way of “Override other clients with the currently used client data”.
This means, all other Firefox browsers linked to your Sync account will get overridden with data found in client you’re currently using (in which you’ll initiate the override).
How to force re-syncing override
Click 3 horizontal lines menu button (Open Menu) in the top right corner and select Options… Or copy about:preferences#sync into your URL bar…
You’ll see this…
Now click Disconnect button and wait for few seconds, just to be sure server refreshes the state correctly.
Then just reconnect back and Sync service will think you’re hooking up a new client, force re-syncing data from it to all other clients, effectively force refreshing ALL clients connected to your account.
This should fix all the cases when clients aren’t syncing as they should. A lot easier and faster than reinstalling entire browser clean like I used to do it until I found out this does the trick as well.
Hope this helps 🙂