Synchronisation gone bad

Description of the issue: Opened my old computer today only to find out that the brave sync removed my latest bookmark on my phone.

I was assuming that since my mobile has the most recent change the sync would add to what is on the computer instead it seems some bizarre merge happened.

Is there a way to revert to before the sync?

Steps to Reproduce (add as many as necessary): 1. 2. 3.
Open my computer and brave which I hadn’t in months
Bookmark seems to update
Go back to my phone to look into a bookmark and cannot find it and then realised these bookmarks have been removed

Reproduces how often:
Just once which is already too much

Brave Version(See the About Brave page in the main menu):
Brave 1.76.81, Chromium 134.0.6998.166

Type of devices currently running on the Sync chain in question:
OnePlus 9Pro
MacBook Pro 2015

Additional Information:
This happened today around 0800 CET

Any chances to get a reply to know what can be done?

Brave Community member @Saoiray has a lot of experience with Brave Sync. Worth the wait, for him to help you. Hang in there.

1 Like

Any chance to get a reply on this @Saoiray ?

@akougblenou sorry I missed this topic the first time tagged. I’m not entirely sure what you’re saying. Maybe I just need a little more time to wake up. But let me try walking you through things based on how it typically is supposed to work:

  1. We start the sync chain on one device. That device begins sending data to the server, which will then be available to itself and other connected devices.

  2. When other devices are added, the server gathers data from both the original and the new device. It then ensures all connected devices receive the combined data. In other words, the newer device will be updated with the existing data from the other one. Nothing is removed in this step.

  3. Once everything is balanced, any action taken on one device will be reflected across all others in the sync chain. For example, if all devices have a bookmark to example.site and I delete it on my Android device, then it will be deleted across the rest of the synced devices too. If my Android still had the bookmark and hadn’t been used in a long time but remained synced, then once it is turned back on, it would fetch the updates and reflect the changes I made while it was inactive.

When bookmarks are deleted, there’s no simple way to restore them. In some cases, if you’re on a desktop system, a restore might be possible using the User Data folder to recover bookmarks from before they were deleted. But you might need to temporarily disable bookmark sync to avoid the system pulling in updates and removing the restored data. I’m not sure what would happen if the device stayed connected during that process. In theory, it might try to re-sync based on the server’s data and undo the restoration.

On mobile devices, unfortunately, deleted bookmarks are usually gone permanently with no way to recover them.

It sounds like you’re saying your case is a little different. It seems like the older data was restored and overwrote the newer data on the phone. That isn’t how sync is normally supposed to behave, so that definitely sounds unusual.

The best thing I can do at this point is tag @Mattches from Brave. He may be able to provide a more in-depth explanation or help resolve the issue.

@Saoiray’s breakdown here is accurate and as far as I know, your data shouldn’t have been “removed” from either device. Sync is only additive unless you manually delete an item. So when you opened your old computer your assumption of the behavior is correct and is what should have happened – there should have been a “merger” of the data that was on your old pc and your current Android device. Sync isn’t really allowed to just “remove”/“delete” things.

How many bookmarks were “removed”? Have you confirmed 100% that the data is not present on either device?

This is exactly how it felt it happened.

I do not know if the sync was fully finalised and I haven’t touched it since.

we are talking abotu possibly a 1000 of record missing I will double check again but last time I checked the data was missing from both the new and old phone: some folders were missing.

All written here by @Matchess and @Saoray is completely correct.

Sync does not delete any records unless they were removed on other device.

There is no way to restore bookmarks on Android.

The described behavior is completely unexpected.

I am going to try reproduce this bug by installing old Brave versions on Android and macOS and upgrading Android only.

I am going to reopen both browser to see if the sync will finalised (maybe it was not completed)
Then maybe some of the links have been moved to other folders somehow (but I doubt that)