killuallnow198019801980 said

Either does not synchronize the data, either is too slow to do it or it DOES whatever it wants... Last time I used it, I logged from Sync in a PC. I changed stuff to another that was still connected to Sync and waited to be sychronized online. Then I logged in to Sync again from the other PC. In a way I kept a BackUp and fixed things in the way I wanted. Imageine what happened. Every bookmark changed according to the other Synced devices and bookmarks of the new device added to Sync were deleted. So, when I add a new device to Sync it has to have NO Bookmarks. But the OLD Sync DID sychronized even the bookmarks of the NEW device added.

Before that happens I synced my mobile phone for 2nd time... The first time it synced all the PC Bookmarks as different category. When I used firefox again the data from the mobile(PC bookmarks) resynced but they were Old ones. All the devices connected to Sync have now this OLD archive.

First, Sync sends data to the Sync server in small batches, not always real time in a continuous stream of data until all the changes are sent to or received from the Sync server. Based upon my observations with using Sync, when rearranging bookmarks the first few changes to bookmarks does tend to send those changes almost immediately, but then Firefox starts to save the changes and send them when it feels like sending them to the server. I suspect part of the delay may be due to the load on the Sync server that the user's account is sitting on (a shared server with thousands of other Firefox Accounts), while other delays may be due to how Sync on each device manages data that will be sent to Sync, along with many other users using Firefox at the same time. IOW, the Sync server needs to balance the load that it is placed under.

Second, "mobile" versions of Firefox (Firefox for Android and Firefox for iOS) handle bookmarks data differently that the desktop (/ laptop) version handles bookmarks data. And the Sync server sits in the middle to decide which data is from / for a "mobile" version and a desktop version, which can slow down the exchange of data with the devices.

Third, Sync is intended to be used all the time, not turned off when the user wants to synchronize their data. You did say "Last time I used it, I logged from Sync in a PC."

Last, best practice is to dis-connect from Sync when re-arranging bookmarks (especially when a "mobile" device is connected to the Sync account) then once the changes are complete connect back to Sync and let that device stay connected to Sync for quite awhile so it can send all those changes to the Sync server. IOW, don't close Firefox immediately after re-arranging your bookmarks. And as other devices are turned on and Firefox is launched, give Sync some time to send those changes to the other devices.

the-edmeister said

Last, best practice is to dis-connect from Sync when re-arranging bookmarks (especially when a "mobile" device is connected to the Sync account) then once the changes are complete connect back to Sync and let that device stay connected to Sync for quite awhile so it can send all those changes to the Sync server. IOW, don't close Firefox immediately after re-arranging your bookmarks. And as other devices are turned on and Firefox is launched, give Sync some time to send those changes to the other devices.

In the past , following those lines, I had duplicated the bookmarks in my account. Because Sync did sychronize the Online data with the new ones. It did NOT erase something that it supposed NOT to know.

That's why I logged off Sync. made the changes and logged in again. I kept the copy on the other one. But when I erased everything from the PC I hadn't logged off, it erased everything on the online database.... Now I loggin from the other. It should fill the database with the new device as NO DATABASE exhisted... Still, it erased everything to the NEW device.. The fixed backup copy! So no BackUp. Nothing. Everything erased!