Hi,

Could you please give some more details on what happened? Are you sure Sync is the cause?

Hi Denys.

I can't be 100% sure. I just hadn't noticed that happened while using Firefox before. I had just recently activated sync, like 1-2-3 days before that happened. I open FF on my macbook like 2 days after using it on the Android phone with sync activated and the tabs and all the groups had disappeared. Only a single or a few tabs were open. I didn't find a way to restore previous session with the groups .

Of course it could have been something else coinciding in time. I'm not even 100% sure I didn't open FF on my macbook even once before that happened. Only thing I know 100% is that syncing wasn't active before, and that I hadn't experienced this before (but also was using FF less frequently).

After this incident, I just turned sync off and used a backup to restore the whole profile, and fortunately the important tabs and group were there... Not being sure if sync is uni or bidirectional, specially after the first sync, and not having a simple way to recover all tabs in their groups in their last state, made me not confident, so I've just left syncing turned off to reduce possible (most likely from my un-expert/single-experience point of view) causes .

Let me know if you need further specific info. Best,

C Martin